Bacterial ethanolamine access, deamination and acetaldehyde disposition

Ethanolamine reaches a compatible adenosylcobamide-dependent EutB/EutC complex through condition-dependent protein transport or experimentally supported diffusion. The enzyme releases acetaldehyde and ammonium. The oxidative pathway routes acetaldehyde to acetyl-CoA through EutE or to acetate through a non-acylating NAD-dependent aldehyde dehydrogenase. A parallel EutG branch forms ethanol and can regenerate NAD+. Selected implementations couple EutD and acetate kinase to CoA recycling and ATP formation, use EutA to replace inactivated cofactor, or organize enzymes in a bacterial microcompartment. The chemical nitrogen-release, oxidative and reductive endpoints are distinct from sustained native carbon growth.

MODULE:bacterial_ethanolamine_uptake_catabolismCOMPLETECONCRETEMetabolic Pathwaymodules/bacterial_ethanolamine_uptake_catabolism.yaml

ethanolamine catabolic processGO:0046336

file:PSEPK/eutC/eutC-deep-research-openscientist.md

OpenScientist gene research for PSEPK EutC

Retained provider research context; unsupported proteome-wide absence claims are not used as primary evidence.

file:PSEPK/eutC/eutC-bioinformatics/RESULTS.md

KT2440 bacterial microcompartment shell-protein inventory

Reproducible UniProt query showing no BMC shell-protein signatures in the KT2440 proteome (with an E. coli positive control), supporting a shell-less implementation of the pathway in that exemplar.

file:projects/P_PUTIDA/data/psepk_pathway_partition.tsv

PSEPK pathway partition

Provides exact KT2440 accessions and exposes the misleading KEGG ppu00564 placement of eutBC, which is treated as a database bucket rather than the pathway boundary.

PMID:20234377

Short eutBC loci occur in multiple bacterial groups; the enterobacterial operon is one realization rather than a universal gene checklist.

Actinobacteria and most Proteobacteria have short eut operons containing eutBC

PMID:29463652

Increasing protonation at acidic pH changes access requirements; EutH/Eat are condition-dependent transport implementations.

the proportion of EA that is protonated increases

PMID:34034083

Ethanolamine microcompartments are a characterized instance of protein-based metabolic compartmentation.

One of the first discovered and characterized microcompartments are those involved in ethanolamine degradation.

PMID:35880884

The Acinetobacter enzyme supported heterologous ethanolamine nitrogen use without imposing a universal metabolosome or EutA requirement.

did not require the metabolosome, the reactivase EutA enzyme

PMID:23585538

EutD and EutG were assigned to CoA and NAD recycling branches.

These are EutD (acetyl-CoA to acetyl phosphate) and EutG (acetaldehyde to ethanol).

PMID:41032589

EutG is an LT2 compartment cargo.

The location of another cargo protein, EutG, was not affected in both ΔeutC2–19 and ΔeutE2–21

PMID:14996820

The reverse phosphotransacetylase product was chemically verified.

High-pressure liquid chromatography and mass spectrometry verified that acetyl-coenzyme A was the product of the reaction.

PMID:26448059

Coupled assays support forward EutD chemistry.

used the phosphotransacetylase EutD to generate AcP from AcCoA and ortho-phosphate.

PMID:35785499

LT2 EutA directly associates with its cognate lyase.

SeEAL and SeEutA interacted and stabilized each other by forming a complex.

PMID:15466038

E. coli EutA restores lyase by cobalamin exchange.

reactivation and activation occur through the exchange of modified coenzyme for free intact adenosylcobalamin.

PMID:15466042

conditional substrate access: LT2 conditions; threshold concerns free uncharged substrate and growth, not a transporter Km or universal taxon threshold. Full-source provenance is in the delivered SALTY EutH source analysis.

When a lowered pH and/or ethanolamine concentration reduced the Eth0 concentration below 25 microM, EutH was needed to facilitate diffusion.

PMID:22267508

non-acylating acetaldehyde oxidation: PAO1 HdhA/PA4022 and PA1984 ExaC recombinant assays, NAD+ at pH9. The Q9ZAA1 reference is ATCC17933 and is not the directly assayed PA1984 protein.

We found here that purified rHdhA and rExaC both oxidize acetaldehyde.

PMID:16291677

conditional EutA/native growth: Abstract-level Salmonella physiology. EutA is not universally required even for all Salmonella growth conditions; toxin management/oxygen context matters.

Neither GSH nor EutA was needed during growth on ethanolamine under reduced-oxygen conditions.

PMID:33850044

coexisting oxidative/reductive fates: EGDe anaerobic defined-medium metabolite data.10403S was used for gene-disruption/EET tests.2:1 product ratio is incompatible with assuming a universally closed1:1 EutE/EutG NAD cycle; additional electron disposal is needed/inferred.

15 mM EA was converted into about 6.6 mM acetate and 3.4 mM ethanol

PMID:19762342

EutB and EutC are the large and small subunits of an alpha6-beta6 enzyme.

The eutB and eutC genes in the eut operon encoded the large and small subunits of the enzyme, respectively. The enzyme existed as the heterododecamer alpha(6)beta(6).

PMID:20519496

Active site in the EutB TIM barrel; cobalamin bound at the alpha/beta interface.

The active site is in the (beta/alpha)(8) barrel of the alpha-subunit; the beta-subunit covers the lower part of the cobalamin that is bound in the interface of the alpha- and beta-subunits.

PMID:21803884

Purified recombinant Salmonella EutE has acetaldehyde dehydrogenase activity of 68.07 umol/min/mg and acetyl-CoA reductase activity of 49.23 umol/min/mg, so the enzyme runs the acylating reaction in both directions.

In vitro assays showed that this enzyme had both acetaldehyde dehydrogenase activity (68.07 ± 1.63 μmol min(-1) mg(-1)) and the desired acetyl-CoA reductase activity (49.23 ± 2.88 μmol min(-1) mg(-1)).

PMID:16272400

Ethanolamine is catabolised to acetyl-CoA, which enters the glyoxylate bypass and the TCA cycle to generate energy and central metabolites.

This report shows that Salmonella enterica catabolizes ethanolamine to acetyl-CoA (Ac-CoA), which enters the glyoxylate bypass and tricarboxylic acid cycle for the generation of energy and central metabolites.

PMID:19783625

Comparative genomics identifies EutBC as the conserved deamination step, while accessory architecture varies.

Ethanolamine-ammonia lyase, the enzyme that breaks ethanolamine into acetaldehyde and ammonia, is encoded by the gene tandem eutBC.

PMID:27325678

PAO1 has a non-acylating ethanolamine pathway; operon evidence complements direct PA4022 biochemical assays.

This pathway is encoded by the PA4022-eat-eutBC operon and consists of a transport protein (Eat), an ethanolamine-ammonia lyase (EutBC), and an acetaldehyde dehydrogenase (PA4022).

The root retains EutBC plus an oxidative acetaldehyde fate as required chemical roles. Protein uptake is conditional, with substrate access and active compatible adenosylated cobamide mandatory environmental prerequisites. A separately evaluated EutBC endpoint measures nitrogen liberation; it does not establish the complete oxidative module or nitrogen assimilation. Oxidative and reductive branches can coexist. Optional parts do not prove diffusion, redox closure, cofactor maintenance or shell assembly. The production compiler ignores context, chemicals and complex active-unit expansion, so the scoped evaluator must enforce these explicitly and distinguish unsupported evidence from biological impossibility. Bacterial scope denotes a reusable mechanism sampled across Pseudomonadota and Bacillota, not universal bacterial presence or exclusion from other domains. EutC contributes to the assembled EutBC enzyme; source enables qualifiers remain preserved in gene reviews and are interpreted with source-specific cautions. PA4022 has direct purified native/recombinant biochemical evidence, whereas Q9ZAA1 ExaC is the ATCC17933 comparator and is not PAO1 PA1984. EutE/PduP and broad ALDH families mix substrates; EutG and EutQ scopes likewise do not license whole-subfamily activity transfers. The LT2 EutQ N-terminal scaffold cannot be generalized to shorter Gram-positive homologs. The older outside-compartment EutBC hypothesis is superseded by newer localization/encapsulation evidence. Known shell-negative reference-proteome searches support only their sampled genome and search sensitivity. No PANTHER ancestral node or exact accession is invented for the Acinetobacter physiological comparator.

13Nodes

8Parts

2Variant Sets

4Variants

10Annotons

11Connections

Derived QC

Recommended-field compliance

100.0% recommended fields populated

All recommended fields populated.

Module deep research

✗ none found

No MODULE:bacterial_ethanolamine_uptake_catabolism deep-research report alongside the module YAML.

Leaf nodes lacking representative members

✓ every leaf node grounds to a representative protein.

Template conformance

✓ every declared conforms_to bundle matches its template motif.

Function consistency and core coverage

11 gene-function check(s) reflected in core functions · 0 conflict(s) · 7 evidence or coverage gap(s) (21 comparison(s))

Retained noncore functions are reported separately; they do not require promotion to core functions. Support from representative genes does not establish conservation across the whole family. Missing reviews or identifiers leave a claim unverified.

Annoton	Participant	Function	Assessment
euth_transport_activity	EutH (Salmonella Typhimurium LT2) UniProtKB:P41796 Family Representative	ethanolamine transmembrane transporter activity GO:0034228	Core Supported The GO molecular function is reflected in core_functions (exact term or a reviewed subclass).
euth_transport_activity	EutH (Listeria monocytogenes 10403S) UniProtKB:A0A0H3GFN0 Family Representative	ethanolamine transmembrane transporter activity GO:0034228	Core Supported The GO molecular function is reflected in core_functions (exact term or a reviewed subclass).
apc_ethanolamine_transport_activity	PP_0544 (Pseudomonas putida KT2440) UniProtKB:Q88QF0 Family Representative	ethanolamine transmembrane transporter activity GO:0034228	Core Supported The GO molecular function is reflected in core_functions (exact term or a reviewed subclass).
eutbc_complex_activity	PROTEIN_COMPLEX Gene	ethanolamine ammonia-lyase activity GO:0008851	Participant Unchecked No direct UniProt participant to compare. Abstract selectors and complex-wide activities cannot be inferred from donor or subunit gene reviews.
eute_acetylating_activity	EutE (Salmonella Typhimurium LT2) UniProtKB:P41793 Family Representative	acetaldehyde dehydrogenase (acetylating) activity GO:0008774	Core Supported The GO molecular function is reflected in core_functions (exact term or a reviewed subclass).
aldb_acetaldehyde_dehydrogenase_activity	ExaC (Pseudomonas aeruginosa ATCC17933) UniProtKB:Q9ZAA1 Family Representative	acetaldehyde dehydrogenase (NAD+) activity GO:0140087	Core Supported The GO molecular function is reflected in core_functions (exact term or a reviewed subclass).
aldb_acetaldehyde_dehydrogenase_activity	PA4022 (Pseudomonas aeruginosa PAO1) UniProtKB:Q9HX05 Family Representative	acetaldehyde dehydrogenase (NAD+) activity GO:0140087	Core Supported The GO molecular function is reflected in core_functions (exact term or a reviewed subclass).
acetaldehyde_reduction_activity	eutG (Salmonella Typhimurium LT2) UniProtKB:P41795 Family Representative	ethanol dehydrogenase (NAD+) activity GO:0120542	Core Supported The GO molecular function is reflected in core_functions (exact term or a reviewed subclass).
eutd_coa_recycling_activity	eutD (Salmonella Typhimurium LT2) UniProtKB:P41790 Family Representative	phosphate acetyltransferase activity GO:0008959	Core Supported The GO molecular function is reflected in core_functions (exact term or a reviewed subclass).
acetate_kinase_energy_conservation_activity	eutQ (Salmonella Typhimurium LT2) UniProtKB:Q9ZFV5 Family Representative	acetate kinase activity GO:0008776	Core Supported The GO molecular function is reflected in core_functions (exact term or a reviewed subclass).
eutbc_reactivation_activity	eutA (Salmonella Typhimurium LT2) UniProtKB:Q9ZFV2 Family Representative	enzyme activator activity GO:0008047	Core Supported The GO molecular function is reflected in core_functions (exact term or a reviewed subclass).
lt2_eutq_cargo_scaffold_activity	eutQ (Salmonella Typhimurium LT2) UniProtKB:Q9ZFV5 Family Representative	protein complex scaffold activity GO:0140378	Core Supported The GO molecular function is reflected in core_functions (exact term or a reviewed subclass).
euth_transport_activity	EutH ethanolamine permease family PANTHER:PTHR40089:SF1 Family	ethanolamine transmembrane transporter activity GO:0034228	Family Supported Family review supports GO:0034228 FAMILY_WIDE. This is the function the family is named for and the term InterPro2GO attaches to IPR007441. It is demonstrated for the Salmonella member (conditional, pH-dependent requirement for ethanolamine use, ethanolamine toxicity, membrane localization) and corroborated in vivo for the Listeria member in the same acid-dependent way, which spans the gammaproteobacterial and firmicute halves of the cached family. The term is kept family-wide rather than subfamily-scoped because PANTHER declares a single subfamily, so there is no axis on which to restrict it; the one member for which the substrate has never been tested, B. subtilis YxeR, is recorded as a member exception rather than as a reason to narrow the family-level term.
apc_ethanolamine_transport_activity	APC-superfamily ethanolamine permeases InterPro:IPR004757 Family	ethanolamine transmembrane transporter activity GO:0034228	Family Review Missing No supported structured family review is available for InterPro:IPR004757.
eute_acetylating_activity	acetylating EutE family PANTHER:PTHR11699:SF68 Family	acetaldehyde dehydrogenase (acetylating) activity GO:0008774	Family Function Unreviewed Family review leaves GO:0008774 UNRESOLVED. CoA-acylating aldehyde oxidation is the diverged reaction of the EutE/PduP branch (SF68), and is not a property of the non-acylating classical ALDHs that make up the rest of the family, which yield the free carboxylate. Within SF68, Salmonella EutE (P41793) has acetaldehyde-to-acetyl-CoA activity on direct assay (PMID:21803884) and E. coli EutE (P77445) is its ortholog, but PANTHER 19.0 (Salmonella classification file) also places Salmonella PduP (Q9XDN1) in SF68, and UniProt records PduP's reaction as the CoA-acylation of propanal in 1,2-propanediol degradation. The acetaldehyde-specific term therefore cannot be granted to the whole subfamily without asserting it for PduP, whose acetaldehyde activity is not reviewed here, and no residue site separating the two substrate preferences is known. The term is left per-member: the bacterial_ethanolamine_uptake_catabolism module selects SF68 for membership and grounds the activity on the EutE representative's own gene review.
aldb_acetaldehyde_dehydrogenase_activity	AldB/AcoD-like non-acylating aldehyde dehydrogenases PANTHER:PTHR43111:SF1 Family	acetaldehyde dehydrogenase (NAD+) activity GO:0140087	Family Function Unreviewed Family review leaves GO:0140087 UNRESOLVED. Cannot be scoped at family level, and must not be inherited. Acetaldehyde is the established substrate for P. aeruginosa ExaC and for Cupriavidus AcoD, but other members of the same single subfamily act on fluoroacetaldehyde, long-chain alkanals or CoA-semialdehydes, so the term is a per-member claim that needs that member's own evidence. PANTHER offers no subfamily that separates the acetaldehyde-specific members, and no residue site is known that would predict substrate preference, so neither SUBFAMILY_ONLY nor RESIDUE_DETERMINED can be used honestly here; this is recorded as undecided at family level rather than resolved the wrong way. The P. aeruginosa PAO1 member PA4022 (Q9HX05) has directly assayed NAD-dependent acetaldehyde oxidation in PMID:22267508; the former ISS-only account overlooked that primary study. This strengthens the individual-member claim without resolving substrate specificity across the whole family.
acetaldehyde_reduction_activity	Acetaldehyde reduction and NAD regeneration PANTHER:PTHR11496:SF94 Family	ethanol dehydrogenase (NAD+) activity GO:0120542	Family Function Unreviewed Family review leaves GO:0120542 UNRESOLVED. Positive support is retained for the ADH4/AdhB enzymes in SF102 and for Salmonella LT2 EutG P41795 in SF94. The latter has native physiological evidence for acetaldehyde reduction and NAD recycling, not purified target kinetics. The official tree places P41795 and E. coli P76553 in SF94, but the former SF102-only restriction wrongly excluded this positive member. SF102 itself mixes substrate specificities, and no whole-SF94 kinetic or residue-level conservation claim is made. Thus neither a family-wide nor an exhaustive whole-subfamily grant expresses the experimentally bounded scope. The exact prior judgment and complete original review are archived in source-analysis/ethanolamine-scope-reassessment.json; this uncertainty concerns scope, not rejection of the positive members.
eutd_coa_recycling_activity	Acetyl-CoA conversion to acetyl phosphate PANTHER:PTHR43356:SF1 Family	phosphate acetyltransferase activity GO:0008959	Family Function Unreviewed Family review leaves GO:0008959 UNRESOLVED. Direct LT2 EutD acetyl-transfer chemistry is established, and Pta members in SF3 also support this activity. SF2 contains both phosphate butyryltransferases and the annotated Methylorubrum Pta C5B1T5; excluding all SF2 would mistake incomplete scope knowledge for a negative activity claim, whereas granting all SF2 acetyl specificity would ignore real donor diversity. The family schema cannot express a positive member subset across these mixed groups. Retain the exact acetyl activity on independently supported members without a family-wide or exhaustive whole-subfamily grant. Ethanolamine pathway membership remains a separate claim.
acetate_kinase_energy_conservation_activity	Acetate kinase ATP formation PANTHER:PTHR36169:SF1 Family	acetate kinase activity GO:0008776	Family Function Unreviewed Family review leaves GO:0008776 UNRESOLVED. Directly demonstrated on LT2 Q9ZFV5, including both reaction directions; neither the family nor SF1 isolates the experimentally grounded bacterial group from fungal members. No family-wide or whole-SF1 grant is justified solely by the label. Lack of broader assays does not imply a negative activity claim.
eutbc_reactivation_activity	Damaged-cofactor exchange and EutBC reactivation PANTHER:PTHR32432:SF13 Family	enzyme activator activity GO:0008047	Family Supported Family review supports GO:0008047 for PANTHER:PTHR32432:SF13. EutA increases EutBC catalytic capacity through cofactor exchange/reactivation. E. coli purified-protein chemistry and LT2 cognate-partner evidence support the EutA SF13 branch, including the requirement for appropriate substrate-enzyme recognition. This does not establish generic unfolding/refolding or activation by the FtsA and EutJ/PilM branches.
lt2_eutq_cargo_scaffold_activity	LT2 EutQ shell-cargo scaffold PANTHER:PTHR36169:SF1 Family	protein complex scaffold activity GO:0140378	Family Function Unreviewed Family review leaves GO:0140378 UNRESOLVED. Supported for LT2 Q9ZFV5 by physical shell/cargo interactions, N-terminal perturbations and assembly phenotypes. Gram-positive homologues lack the first three implicated helices, and fungi occupy the same SF1. The family schema cannot express the experimentally bounded LT2 architectural subset as a whole-subfamily grant; no new PTN or conserved residue rule is invented.

Gene-review completeness (20/20 grounded genes reviewed)

18 complete review(s) · 1 with deep research · 0 missing review · 19 reviewed but lacking deep research

Gene	Review	Complete	Deep research
eutA Q9ZFV2	✓	✓	✗
eutB A0A0H3GBB1	✓	✓	✗
eutB P0AEJ6	✓	✓	✗
eutB P19264	✓	12/13	✗
eutB Q88QF1	✓	7/8	✗
eutB Q9HX03	✓	✓	✗
eutC A0A0H3GFM0	✓	✓	✗
eutC P19265	✓	✓	✗
eutC P19636	✓	✓	✗
eutC Q88QF2	✓	✓	✓
eutC Q9HX02	✓	✓	✗
eutD P41790	✓	✓	✗
eutE P41793	✓	✓	✗
eutG P41795	✓	✓	✗
eutH A0A0H3GFN0	✓	✓	✗
eutH P41796	✓	✓	✗
eutQ Q9ZFV5	✓	✓	✗
exaC Q9ZAA1	✓	✓	✗
PA4022 Q9HX05	✓	✓	✗
PP_0544 Q88QF0	✓	✓	✗

Tree

Bacterial ethanolamine access, deamination and acetaldehyde dispositionMetabolic Pathwaybacterial_ethanolamine_uptake_catabolism

Parts
1. 1. ethanolamine uptake optional
2. Ethanolamine transmembrane uptakeTransport Stepethanolamine_uptake
  
  Variants
  1. Ethanolamine transporter implementations by transporter family [Realizer] (One Or More)
    
    Classical EutH-family uptakeTransport Stepclassical_euth_transport
    
    Annotons
    
    EutH ethanolamine permease Family: EutH ethanolamine permease family
    
    APC-family ethanolamine-permease uptakeTransport Stepapc_ethanolamine_permease_transport
    
    Annotons
    
    APC-family ethanolamine permease Family: APC-superfamily ethanolamine permeases
3. 2. cobalamin-dependent ethanolamine deamination
4. EutB/EutC ethanolamine ammonia-lyase reactionReactioneutbc_ethanolamine_deamination
  
  Annotons
  - Cobalamin-dependent EutB/EutC ammonia-lyase Protein Complex: bacterial ethanolamine ammonia-lyase complex
5. 3. acetaldehyde oxidation
6. Oxidation of EutBC-derived acetaldehydeMetabolic Pathwayacetaldehyde_oxidation
  
  Variants
  1. Acetaldehyde oxidation routes by carbon product and CoA dependence [Route] (One Or More)
    
    Acetylating EutE route to acetyl-CoAReactionacetylating_eute_route
    
    Annotons
    
    EutE acetaldehyde dehydrogenase (acetylating) Family: acetylating EutE family
    
    Non-acylating ALDH route to acetateReactionnon_acylating_aldh_route
    
    Annotons
    
    Non-acylating NAD-dependent acetaldehyde dehydrogenase Family: AldB/AcoD-like non-acylating aldehyde dehydrogenases
7. Acetaldehyde reduction and NAD regeneration optional
8. Acetaldehyde reduction and NAD regenerationReactionacetaldehyde_reduction
  
  Annotons
  - Acetaldehyde reduction and NAD regeneration Family: Acetaldehyde reduction and NAD regeneration
9. Acetyl-CoA conversion to acetyl phosphate optional
10. Acetyl-CoA conversion to acetyl phosphateReactioneutd_coa_recycling
  
  Annotons
  - Acetyl-CoA conversion to acetyl phosphate Family: Acetyl-CoA conversion to acetyl phosphate
11. Acetate kinase ATP formation optional
12. Acetate kinase ATP formationReactionacetate_kinase_energy_conservation
  
  Annotons
  - Acetate kinase ATP formation Family: Acetate kinase ATP formation
13. Damaged-cofactor exchange and EutBC reactivation optional
14. Damaged-cofactor exchange and EutBC reactivationMolecular Functioneutbc_reactivation
  
  Annotons
  - Damaged-cofactor exchange and EutBC reactivation Family: Damaged-cofactor exchange and EutBC reactivation
15. LT2 EutQ shell-cargo scaffold optional
16. LT2 EutQ shell-cargo scaffoldMolecular Functionlt2_eutq_cargo_scaffold
  
  Annotons
  - LT2 EutQ shell-cargo scaffold Family: LT2 EutQ shell-cargo scaffold

Details

Context

bacteriaNCBITaxon:2

Intracellular ethanolamine access Compatible active adenosylated cobamide Branch-specific redox and CoA availability

PMID:15466042

When a lowered pH and/or ethanolamine concentration reduced the Eth0 concentration below 25 microM, EutH was needed to facilitate diffusion.

PMID:35880884

nitrogen endpoint versus carbon-growth endpoint: Native ATCC17978, Fig4. Host ammonia assimilation and other metabolic machinery are present; EutBC is not an autonomous biomass pathway.

Chromosomal levels of eutBC expression were sufficient to support growth with ethanolamine as a nitrogen source

PMID:29463652

Increasing protonation at acidic pH changes access requirements; EutH/Eat are condition-dependent transport implementations.

the proportion of EA that is protonated increases

file:PSEAE/PA4022/PA4022-source-analysis/primary-assay-scope.yaml

PAO1 carbon-growth witness at tested pH7/20mM; Eat dispensability establishes access without Eat, not a unique physical transport mechanism.

The growth of the Δ eat mutant on ethanolamine was identical to that of wild-type (WT) P. aeruginosa PAO1

file:PSEAE/PA4022/PA4022-source-analysis/primary-assay-scope.yaml

PAO1 carbon-growth witness at tested pH7/20mM; Eat dispensability establishes access without Eat, not a unique physical transport mechanism.

Deletion of the PA4022 gene reduced the growth of P. aeruginosa PAO1 on ethanolamine as a sole source of carbon

Bacterial ethanolamine access, deamination and acetaldehyde dispositionMetabolic Pathwaybacterial_ethanolamine_uptake_catabolism

ethanolamine catabolic processGO:0046336

Context

bacteriaNCBITaxon:2

Intracellular ethanolamine access Compatible active adenosylated cobamide Branch-specific redox and CoA availability

PMID:15466042

When a lowered pH and/or ethanolamine concentration reduced the Eth0 concentration below 25 microM, EutH was needed to facilitate diffusion.

PMID:35880884

nitrogen endpoint versus carbon-growth endpoint: Native ATCC17978, Fig4. Host ammonia assimilation and other metabolic machinery are present; EutBC is not an autonomous biomass pathway.

Chromosomal levels of eutBC expression were sufficient to support growth with ethanolamine as a nitrogen source

PMID:29463652

Increasing protonation at acidic pH changes access requirements; EutH/Eat are condition-dependent transport implementations.

the proportion of EA that is protonated increases

file:PSEAE/PA4022/PA4022-source-analysis/primary-assay-scope.yaml

PAO1 carbon-growth witness at tested pH7/20mM; Eat dispensability establishes access without Eat, not a unique physical transport mechanism.

The growth of the Δ eat mutant on ethanolamine was identical to that of wild-type (WT) P. aeruginosa PAO1

file:PSEAE/PA4022/PA4022-source-analysis/primary-assay-scope.yaml

PAO1 carbon-growth witness at tested pH7/20mM; Eat dispensability establishes access without Eat, not a unique physical transport mechanism.

Deletion of the PA4022 gene reduced the growth of P. aeruginosa PAO1 on ethanolamine as a sole source of carbon

Connections

ethanolamine_uptake -> eutbc_ethanolamine_deamination Provides Input For

Conditional protein transport supplies ethanolamine; documented diffusion is an alternative access condition, not an empty protein branch.

Context

Protein-mediated access implementation

PMID:15466042

When a lowered pH and/or ethanolamine concentration reduced the Eth0 concentration below 25 microM, EutH was needed to facilitate diffusion.

eutbc_ethanolamine_deamination -> acetaldehyde_oxidation Provides Input For

EutBC supplies acetaldehyde to one or more supported oxidation routes.

PMID:27325678

PAO1 has a non-acylating ethanolamine pathway; operon evidence complements direct PA4022 biochemical assays.

This pathway is encoded by the PA4022-eat-eutBC operon and consists of a transport protein (Eat), an ethanolamine-ammonia lyase (EutBC), and an acetaldehyde dehydrogenase (PA4022).

eutbc_ethanolamine_deamination -> acetaldehyde_reduction Provides Input For

The parallel EutG branch consumes acetaldehyde to form ethanol.

PMID:23585538

EutD and EutG were assigned to CoA and NAD recycling branches.

These are EutD (acetyl-CoA to acetyl phosphate) and EutG (acetaldehyde to ethanol).

acetylating_eute_route -> acetaldehyde_reduction Provides Input For

EutE-generated NADH can supply EutG in the private-cofactor model; flux balance needs separate evidence.

Context

Supported coupled NAD recycling implementation

PMID:23585538

EutD and EutG were assigned to CoA and NAD recycling branches.

These are EutD (acetyl-CoA to acetyl phosphate) and EutG (acetaldehyde to ethanol).

acetaldehyde_reduction -> acetylating_eute_route Provides Input For

EutG can regenerate NAD+ for oxidative processing in the supported recycling model.

Context

Supported coupled NAD recycling implementation

PMID:23585538

EutD and EutG were assigned to CoA and NAD recycling branches.

These are EutD (acetyl-CoA to acetyl phosphate) and EutG (acetaldehyde to ethanol).

acetylating_eute_route -> eutd_coa_recycling Provides Input For

EutE supplies acetyl-CoA to phosphotransacetylase.

PMID:26448059

Coupled assays support forward EutD chemistry.

used the phosphotransacetylase EutD to generate AcP from AcCoA and ortho-phosphate.

eutd_coa_recycling -> acetylating_eute_route Provides Input For

EutD liberates CoA for another EutE cycle in the defined private-pool architecture.

Context

Supported CoA recycling implementation

PMID:23585538

EutD and EutG were assigned to CoA and NAD recycling branches.

These are EutD (acetyl-CoA to acetyl phosphate) and EutG (acetaldehyde to ethanol).

eutd_coa_recycling -> acetate_kinase_energy_conservation Provides Input For

EutD-generated acetyl phosphate supports kinase-dependent ATP formation in coupled assays.

PMID:26448059

Coupled assays support forward EutD chemistry.

used the phosphotransacetylase EutD to generate AcP from AcCoA and ortho-phosphate.

eutbc_reactivation -> eutbc_ethanolamine_deamination Positively Regulates

EutA restores selected inactivated lyase implementations through cofactor exchange; it is not needed after every normal turnover.

Context

Inactivated enzyme with accessible replacement cofactor and ATP/Mg2+

PMID:15466038

E. coli EutA restores lyase by cobalamin exchange.

reactivation and activation occur through the exchange of modified coenzyme for free intact adenosylcobalamin.

lt2_eutq_cargo_scaffold -> acetylating_eute_route Positively Regulates

LT2 EutQ N-terminal architecture helps couple EutE cargo to shell during assembly.

Context

LT2 scaffold-containing microcompartment implementation

PMID:41032589

LT2 EutQ N-terminal architecture helps couple EutE cargo to shell during assembly.

the N-terminal domain of EutQ mediates the physical binding between the shell and cargos to ensure encapsulation

lt2_eutq_cargo_scaffold -> eutbc_ethanolamine_deamination Positively Regulates

LT2 EutQ shell-cargo coupling supports EutC encapsulation; this is structural context, not catalytic activation of isolated EutB.

Context

LT2 scaffold-containing microcompartment implementation

PMID:41032589

LT2 EutQ shell-cargo coupling supports EutC encapsulation; this is structural context, not catalytic activation of isolated EutB.

the N-terminal domain of EutQ mediates the physical binding between the shell and cargos to ensure encapsulation

Part 1: ethanolamine uptake (optional)

PMID:15466042

When a lowered pH and/or ethanolamine concentration reduced the Eth0 concentration below 25 microM, EutH was needed to facilitate diffusion.

PMID:29463652

Increasing protonation at acidic pH changes access requirements; EutH/Eat are condition-dependent transport implementations.

the proportion of EA that is protonated increases

Protein transporter capacity is optional in root topology, but experimentally qualified access remains mandatory in each endpoint evaluation.

Ethanolamine transmembrane uptakeTransport Stepethanolamine_uptake

Variant set: Ethanolamine transporter implementations by transporter family [Realizer] (One Or More)

Classical EutH-family uptakeTransport Stepclassical_euth_transport

Annotons

EutH ethanolamine permease

euth_transport_activity

Participant: Family: EutH ethanolamine permease family

Family:

EutH ethanolamine permease familyPANTHER:PTHR40089:SF1

Representative Members: EutH (Salmonella Typhimurium LT2)UniProtKB:P41796 EutH (Listeria monocytogenes 10403S)UniProtKB:A0A0H3GFN0

Function

ethanolamine transmembrane transporter activityGO:0034228

Substrates: extracellular ethanolamine

Products: intracellular ethanolamine

Locations

plasma membraneGO:0005886

LT2 EutH supports access when uncharged ethanolamine is limiting; the threshold is an assay-specific growth condition, not a transporter Km. Listeria10403S is a conserved-family/physiology inference, not direct transport kinetics. Proton coupling remains unresolved.

APC-family ethanolamine-permease uptakeTransport Stepapc_ethanolamine_permease_transport

Annotons

APC-family ethanolamine permease

apc_ethanolamine_transport_activity

Participant: Family: APC-superfamily ethanolamine permeases

Family:

APC-superfamily ethanolamine permeasesInterPro:IPR004757

Representative Members: PP_0544 (Pseudomonas putida KT2440)UniProtKB:Q88QF0

Function

ethanolamine transmembrane transporter activityGO:0034228

Substrates: extracellular ethanolamine

Products: intracellular ethanolamine

Locations

plasma membraneGO:0005886

KT2440 PP_0544 is an IPR004757/TIGR00908 candidate supported by conserved architecture and locus context; native transport rate and coupling are not established. PAO1 Eat physiology is comparative evidence and does not convert PP_0544 into a directly assayed transporter.

Part 2: cobalamin-dependent ethanolamine deamination

PMID:19762342

EutB and EutC are the large and small subunits of an alpha6-beta6 enzyme.

The eutB and eutC genes in the eut operon encoded the large and small subunits of the enzyme, respectively. The enzyme existed as the heterododecamer alpha(6)beta(6).

PMID:20519496

Active site in the EutB TIM barrel; cobalamin bound at the alpha/beta interface.

The active site is in the (beta/alpha)(8) barrel of the alpha-subunit; the beta-subunit covers the lower part of the cobalamin that is bound in the interface of the alpha- and beta-subunits.

PMID:35880884

The Acinetobacter enzyme supported heterologous ethanolamine nitrogen use without imposing a universal metabolosome or EutA requirement.

did not require the metabolosome, the reactivase EutA enzyme

EutB/EutC ethanolamine ammonia-lyase reactionReactioneutbc_ethanolamine_deamination

Annotons

Cobalamin-dependent EutB/EutC ammonia-lyase

eutbc_complex_activity

Participant: Protein Complex: bacterial ethanolamine ammonia-lyase complex

Protein Complex:

bacterial ethanolamine ammonia-lyase complexGO:0009350

Active units:

EutB large subunit

Participant: Family: EutB ethanolamine ammonia-lyase large-subunit family

Family:

EutB ethanolamine ammonia-lyase large-subunit familyPANTHER:PTHR39329:SF1

Representative Members: EutB (Pseudomonas putida KT2440)UniProtKB:Q88QF1 EutB (Escherichia coli K-12)UniProtKB:P0AEJ6 EutB (Listeria monocytogenes10403S)UniProtKB:A0A0H3GBB1 EutB (Salmonella Typhimurium LT2)UniProtKB:P19264 EutB (Pseudomonas aeruginosa PAO1)UniProtKB:Q9HX03

Role: Catalytic large subunit containing the active-site TIM barrel.

EutC small subunit

Participant: Family: EutC ethanolamine ammonia-lyase small-subunit family

Family:

EutC ethanolamine ammonia-lyase small-subunit familyPANTHER:PTHR39330

Representative Members: EutC (Pseudomonas putida KT2440)UniProtKB:Q88QF2 EutC (Escherichia coli K-12)UniProtKB:P19636 EutC (Listeria monocytogenes10403S)UniProtKB:A0A0H3GFM0 EutC (Salmonella Typhimurium LT2)UniProtKB:P19265 EutC (Pseudomonas aeruginosa PAO1)UniProtKB:Q9HX02

Role: Small subunit completing the interfacial cobalamin environment.

Function

ethanolamine ammonia-lyase activityGO:0008851

Substrates: ethanolamine

Products: acetaldehyde ammonium

A compatible assembled EutB/EutC pair performs ethanolamine cleavage with active adenosylated cobamide. EutB carries the active-site barrel; EutC completes the interfacial cofactor environment. Neither isolated subunit nor an untested cross-taxon pair is a positive complex witness. E. coli purified structure, native Listeria gene perturbation and inferred KT2440 orthology have distinct evidential scopes.

Part 3: acetaldehyde oxidation

Oxidation of EutBC-derived acetaldehydeMetabolic Pathwayacetaldehyde_oxidation

Variant set: Acetaldehyde oxidation routes by carbon product and CoA dependence [Route] (One Or More)

Acetylating EutE route to acetyl-CoAReactionacetylating_eute_route

Annotons

EutE acetaldehyde dehydrogenase (acetylating)

eute_acetylating_activity

Participant: Family: acetylating EutE family

Family:

acetylating EutE familyPANTHER:PTHR11699:SF68 P41793 belongs to SF68, which also contains PduP. Acetaldehyde-specific reviewed activity is required; membership alone does not distinguish substrate preference.

Representative Members: EutE (Salmonella Typhimurium LT2)UniProtKB:P41793

Function

acetaldehyde dehydrogenase (acetylating) activityGO:0008774

Substrates: acetaldehyde coenzyme A NAD+

Products: acetyl-CoA NADH proton

Classical EutE route that conserves the acetaldehyde carbon as acetyl-CoA.

Non-acylating ALDH route to acetateReactionnon_acylating_aldh_route

Annotons

Non-acylating NAD-dependent acetaldehyde dehydrogenase

aldb_acetaldehyde_dehydrogenase_activity

Participant: Family: AldB/AcoD-like non-acylating aldehyde dehydrogenases

Family:

AldB/AcoD-like non-acylating aldehyde dehydrogenasesPANTHER:PTHR43111:SF1

Representative Members: ExaC (Pseudomonas aeruginosa ATCC17933)UniProtKB:Q9ZAA1 PA4022 (Pseudomonas aeruginosa PAO1)UniProtKB:Q9HX05

Function

acetaldehyde dehydrogenase (NAD+) activityGO:0140087

Substrates: acetaldehyde NAD+ water

Products: acetate NADH protons

Direct PAO1 PA4022/HdhA assays establish NAD-dependent acetaldehyde oxidation. PA4022 belongs to the ethanolamine locus. Q9ZAA1 ExaC is a separate ATCC17933 biochemical comparator, not the PAO1 PA1984 construct. KT2440 AldB substrate preference remains unresolved and is not a positive acetaldehyde witness.

Part: Acetaldehyde reduction and NAD regeneration (optional)

PMID:23585538

Inferred NAD-dependent acetaldehyde reduction to ethanol regenerates NAD+ in the LT2 ethanolamine compartment. The family-supported reaction is reversible; physiological direction and cofactor recycling are supported by genetics, whereas purified target kinetics remain unresolved.

These are EutD (acetyl-CoA to acetyl phosphate) and EutG (acetaldehyde to ethanol).

PMID:41032589

The location of another cargo protein, EutG, was not affected in both ΔeutC2–19 and ΔeutE2–21

A conditional implementation, not a universally required gene or a whole-family activity grant.

Acetaldehyde reduction and NAD regenerationReactionacetaldehyde_reduction

Context

Salmonella enterica subsp. enterica serovar Typhimurium str. LT2NCBITaxon:99287

No purified LT2 EutG kinetics, metal preference, or measured native flux partition established. Compartmental NAD recycling remains a genetically supported physiological model; modern imaging confirms cargo localization.

Annotons

Acetaldehyde reduction and NAD regeneration

acetaldehyde_reduction_activity

Participant: Family: Acetaldehyde reduction and NAD regeneration

Family:

Acetaldehyde reduction and NAD regenerationPANTHER:PTHR11496:SF94

Representative Members: eutG (Salmonella Typhimurium LT2)UniProtKB:P41795

Function

ethanol dehydrogenase (NAD+) activityGO:0120542

Substrates: acetaldehyde NADH proton

Products: ethanol NAD+

Locations

ethanolamine degradation polyhedral organelleGO:0031471

Part: Acetyl-CoA conversion to acetyl phosphate (optional)

PMID:14996820

Reversible phosphate acetyltransferase activity converts acetyl-CoA plus phosphate to acetyl phosphate plus CoA in the catabolic direction, feeding acetate kinase and recycling CoA. Compartment assignment is supported by genetic physiology rather than a direct native EutD localization assay.

High-pressure liquid chromatography and mass spectrometry verified that acetyl-coenzyme A was the product of the reaction.

PMID:26448059

used the phosphotransacetylase EutD to generate AcP from AcCoA and ortho-phosphate.

A conditional implementation, not a universally required gene or a whole-family activity grant.

Acetyl-CoA conversion to acetyl phosphateReactioneutd_coa_recycling

Context

Salmonella enterica subsp. enterica serovar Typhimurium str. LT2NCBITaxon:99287

2004 product confirmation is acetyl-CoA formation in the reverse direction.2016 coupled assays support forward CoA liberation. Compartment localization is physiological inference, not a direct EutD image from41032589.

Annotons

Acetyl-CoA conversion to acetyl phosphate

eutd_coa_recycling_activity

Participant: Family: Acetyl-CoA conversion to acetyl phosphate

Family:

Acetyl-CoA conversion to acetyl phosphatePANTHER:PTHR43356:SF1

Representative Members: eutD (Salmonella Typhimurium LT2)UniProtKB:P41790

Function

phosphate acetyltransferase activityGO:0008959

Substrates: acetyl-CoA phosphate

Products: acetyl phosphate coenzyme A

Locations

ethanolamine degradation polyhedral organelleGO:0031471

Part: Acetate kinase ATP formation (optional)

PMID:26448059

Reversible acetate kinase activity of the LT2 cupin-like C-terminal region generates ATP and acetate from ADP and acetyl phosphate. Direct coupled assays support pathway chemistry; dedicated delivery of this ATP to EutA or EutT remains a hypothesis.

When EutQ, EutP or both were present in the reaction mixture, ATP was formed at the expense of AcCoA

PMID:26448059

S. Typhimurium EutQ acetate kinase activity did not require divalent metal cofactors, as dialysis with EDTA did not affect its activity.

PMID:41032589

Our results show that only EutQ is encapsulated within the Eut BMC

A conditional implementation, not a universally required gene or a whole-family activity grant.

Acetate kinase ATP formationReactionacetate_kinase_energy_conservation

Context

Salmonella enterica subsp. enterica serovar Typhimurium str. LT2NCBITaxon:99287

ATP supply specifically to EutA/EutT is proposed, not demonstrated channeling. EutQ kinase was EDTA-insensitive. Gram-positive homologs lack the first three N-terminal helices, precluding wholesale assembly-role transfer.

Annotons

Acetate kinase ATP formation

acetate_kinase_energy_conservation_activity

Participant: Family: Acetate kinase ATP formation

Family:

Acetate kinase ATP formationPANTHER:PTHR36169:SF1

Representative Members: eutQ (Salmonella Typhimurium LT2)UniProtKB:Q9ZFV5

Function

acetate kinase activityGO:0008776

Substrates: acetyl phosphate ADP

Products: acetate ATP

Locations

ethanolamine degradation polyhedral organelleGO:0031471

Part: Damaged-cofactor exchange and EutBC reactivation (optional)

PMID:15466038

Reactivates cognate ethanolamine ammonia-lyase by ATP-dependent exchange of inactive bound cobalamin for intact adenosylcobalamin. E. coli biochemistry supports this mechanistic assignment to LT2, whose EutA directly associates with EutBC and Eut metabolosomes. Reactivation is needed after inactivation, not after every catalytic turnover.

reactivation and activation occur through the exchange of modified coenzyme for free intact adenosylcobalamin.

PMID:35785499

SeEAL and SeEutA interacted and stabilized each other by forming a complex.

PMID:35785499

Result from TEM immunogold labeling microscopy revealed that the localization patterns of EAL, EutA, and EutT were very similar, and that all of these enzymes associate with Eut metabolosomes

A conditional implementation, not a universally required gene or a whole-family activity grant.

Damaged-cofactor exchange and EutBC reactivationMolecular Functioneutbc_reactivation

Context

Salmonella enterica subsp. enterica serovar Typhimurium str. LT2NCBITaxon:99287

LT2 binding/localization and cognate complementation support homolog transfer of reactivation chemistry. Lumen placement is inferred. Aggregation limited LT2 enzyme kinetics; no exact whole-construct identity or autonomous ATP-folding is asserted. EutA is conditional after lyase inactivation, not mandatory for every turnover.

Annotons

Damaged-cofactor exchange and EutBC reactivation

eutbc_reactivation_activity

Participant: Family: Damaged-cofactor exchange and EutBC reactivation

Family:

Damaged-cofactor exchange and EutBC reactivationPANTHER:PTHR32432:SF13

Representative Members: eutA (Salmonella Typhimurium LT2)UniProtKB:Q9ZFV2

Function

enzyme activator activityGO:0008047

Locations

ethanolamine degradation polyhedral organelleGO:0031471

Part: LT2 EutQ shell-cargo scaffold (optional)

PMID:41032589

The N-terminal helices of LT2 EutQ form a physical scaffold linking shell proteins and cargo enzymes during ethanolamine microcompartment assembly; this is distinct from its C-terminal kinase activity.

the EutQ N-terminal H1/H2 interacts with the shell whereas H3/H4 associates with cargos.

PMID:41032589

Our results show that only EutQ is encapsulated within the Eut BMC

Only the LT2 EutQ scaffold contribution is represented here. A full shell also requires shell proteins and cargo interactions; this annoton alone never establishes complete microcompartment assembly.

LT2 EutQ shell-cargo scaffoldMolecular Functionlt2_eutq_cargo_scaffold

Context

Salmonella enterica subsp. enterica serovar Typhimurium str. LT2NCBITaxon:99287

Annotons

LT2 EutQ shell-cargo scaffold

lt2_eutq_cargo_scaffold_activity

Participant: Family: LT2 EutQ shell-cargo scaffold

Family:

LT2 EutQ shell-cargo scaffoldPANTHER:PTHR36169:SF1

Representative Members: eutQ (Salmonella Typhimurium LT2)UniProtKB:Q9ZFV5

Function

protein complex scaffold activityGO:0140378

Locations

ethanolamine degradation polyhedral organelleGO:0031471