Bacterial alkanesulfonate uptake and FMN-dependent desulfonation

SsuABC-mediated alkanesulfonate uptake can supply an aerobic two-component desulfonation system in which a flavin reductase provides reduced FMN and SsuD cleaves the carbon–sulfur bond to release sulfite and an aldehyde. The sampled native implementations are E. coli K-12 and Pseudomonas putida KT2440 and S-313. Their transporter alternatives, substrate ranges and reductase requirements differ. Sulfite assimilation, TauD chemistry, regulatory induction and aromatic-sulfonate accessory pathways lie outside this boundary.

MODULE:bacterial_alkanesulfonate_uptake_desulfonationCOMPLETECONCRETEMetabolic Pathwaymodules/bacterial_alkanesulfonate_uptake_desulfonation.yaml
alkanesulfonate catabolic processGO:0046306
PMID:10480865
Characterization of a two-component alkanesulfonate monooxygenase from Escherichia coli.
Purified E. coli SsuD converts alkanesulfonate to aldehyde and sulfite. This is direct catalytic evidence for the E. coli implementation and comparative chemistry for Pseudomonas.
The pure enzyme catalyzed the conversion of pentanesulfonic acid to sulfite and pentaldehyde
PMID:10781534
Deletion analysis of the Escherichia coli taurine and alkanesulfonate transport systems.
Native E. coli deletion/complementation distinguishes SsuABC and TauABC systems. It does not test interspecies subunit mixtures.
the individual components of the two transport systems were not functionally exchangeable
PMID:10781557
The ssu locus plays a key role in organosulfur metabolism in Pseudomonas putida S-313.
S-313 sequence/operon analysis identifies the three ABC-transporter components. Growth genetics alone cannot establish individual-subunit necessity.
The first group consists of ssuA , ssuB , and ssuC , which are the genes for a putative ATP-binding cassette (ABC)-type transport system.
file:publications/url_https___backend.orbit.dtu.dk_ws_files_406857921_PhD_Thesis_-_Garret_William_O_Connell.pdf.md
https://backend.orbit.dtu.dk/ws/files/406857921/PhD_Thesis_-_Garret_William_O_Connell.pdf
The 2024 O’Connell thesis supplies native KT2440 ΔssuD and joint ΔssuBC sulfur-utilization genetics, corroborating the locus without proving isolated B/C transport or individual A/E necessity.
Due to the genetic placement of the ssuACB enzymes (Fig S5.), only ssuCB (permease and cytoplasmic ATPase) were disrupted.
PMID:10781557
The ssu locus plays a key role in organosulfur metabolism in Pseudomonas putida S-313.
SsuE-independent aliphatic-sulfonate growth demonstrates an alternative physiological route, while the reduced-FMN supplier remains unidentified.
The flavin reductase SsuE was not required for growth with aliphatic sulfonates or methionine but was needed for growth with arylsulfonates

Exact gene-product selectors prevent broad-family substrate transfer and mixed-species SsuABC assemblies. Family labels are verified classifications of those proteins. SsuE supplies the required reduced-flavin chemistry in each named canonical implementation but is not asserted universally essential: experimentally active S-313 without SsuE is explicitly reconciled as an unresolved biological alternative. No direct-channeling exclusivity, universal donor equivalence, fixed complex stoichiometry or minimal-genotype sufficiency is encoded. Manual source research followed actual provider failures; existing provider reports were discovery aids only. Taxonomic scope was reconsidered in the 2026-11 pass and deliberately left concrete. The Ssu system is not confined to the sampled Gammaproteobacteria: the PANTHER member inventories place Bacillus subtilis SsuA/SsuB/SsuC/SsuD, Acinetobacter baylyi ADP1 SsuB and numerous rhizobial and Burkholderia SsuB/SsuD proteins in the same subfamilies used here, so the uptake plus reduced-flavin desulfonation motif is at least Bacteria-wide in distribution. That breadth is recorded in the four accompanying family reviews (PTHR30024, PTHR30151, PTHR42788, PTHR42847), which carry those organisms as subfamily representatives, rather than by widening this module: the variants here are species-coherent implementations backed by native deletion/complementation or purified-enzyme work, and promoting a Firmicutes or Alphaproteobacteria exemplar to a module variant would require the same depth of gene-level review for its five proteins. The family reviews also record why subfamily membership alone cannot carry substrate specificity across this motif: PTHR42847:SF4 holds both SsuD and the pyrimidine monooxygenase RutA, and PTHR42788 splits SsuB-named proteins across three subfamilies, two of which share an official name.

13Nodes
9Parts
1Variant Sets
3Variants
9Annotons
6Connections

Derived QC

Recommended-field compliance

100.0% recommended fields populated

All recommended fields populated.

Module deep research

✓ present

  • bacterial_alkanesulfonate_uptake_desulfonation-deep-research-openscientist.md (openscientist)

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

6 gene-function check(s) reflected in core functions · 0 conflict(s) · 0 evidence or coverage gap(s) (15 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.

AnnotonParticipantFunctionAssessment
ecoli_ssuabc_activity PROTEIN_COMPLEX
Gene 		ABC-type alkanesulfonate transporter transporter activity
GO:0042959 		Participant Unchecked
No direct UniProt participant to compare. Abstract selectors and complex-wide activities cannot be inferred from donor or subunit gene reviews.
ecoli_ssue_activity ssuE
UniProtKB:P80644
Gene 		FMN reductase [NAD(P)H] activity
GO:0008752 		Core Supported
The GO molecular function is reflected in core_functions (exact term or a reviewed subclass).
ecoli_ssud_activity ssuD
UniProtKB:P80645
Gene 		alkanesulfonate monooxygenase activity
GO:0008726 		Core Supported
The GO molecular function is reflected in core_functions (exact term or a reviewed subclass).
kt2440_ssuabc_activity PROTEIN_COMPLEX
Gene 		ABC-type alkanesulfonate transporter transporter activity
GO:0042959 		Participant Unchecked
No direct UniProt participant to compare. Abstract selectors and complex-wide activities cannot be inferred from donor or subunit gene reviews.
kt2440_ssue_activity ssuE
UniProtKB:Q88R97
Gene 		FMN reductase (NADPH) activity
GO:0052873 		Core Supported
The GO molecular function is reflected in core_functions (exact term or a reviewed subclass).
kt2440_ssud_activity ssuD
UniProtKB:Q88R95
Gene 		alkanesulfonate monooxygenase activity
GO:0008726 		Core Supported
The GO molecular function is reflected in core_functions (exact term or a reviewed subclass).
s313_ssuabc_activity PROTEIN_COMPLEX
Gene 		ABC-type alkanesulfonate transporter transporter activity
GO:0042959 		Participant Unchecked
No direct UniProt participant to compare. Abstract selectors and complex-wide activities cannot be inferred from donor or subunit gene reviews.
s313_ssue_activity ssuE
UniProtKB:O85762
Gene 		FMN reductase (NADPH) activity
GO:0052873 		Core Supported
The GO molecular function is reflected in core_functions (exact term or a reviewed subclass).
s313_ssud_activity ssuD
UniProtKB:O85764
Gene 		alkanesulfonate monooxygenase activity
GO:0008726 		Core Supported
The GO molecular function is reflected in core_functions (exact term or a reviewed subclass).
ecoli_ssue_activity FMN REDUCTASE (NADPH)
PANTHER:PTHR43408:SF1
Family 		FMN reductase [NAD(P)H] activity
GO:0008752 		Family Supported
Family review supports GO:0008752 FAMILY_WIDE. NAD(P)H-dependent reduction of FMN is the activity every characterized member performs, in both subfamilies. E. coli SsuE uses NADH and NADPH at comparable catalytic efficiency, which is what the current definition of this term requires.
ecoli_ssud_activity ALKANESULFONATE MONOOXYGENASE-RELATED
PANTHER:PTHR42847:SF4
Family 		alkanesulfonate monooxygenase activity
GO:0008726 		Family Supported
Family review supports GO:0008726 for PANTHER:PTHR42847:SF4. The term holds for the SsuD orthologs of SF4, which are directly assayed in E. coli and genetically grounded in P. putida, and is defensible for MsuD, since methanesulfonate is itself an alkanesulfonate. It also holds for the sulfoquinovose monooxygenases SmoC and SquD: their reaction (RHEA:70775) is the GO:0008726 transformation applied to the primary alkyl sulfonate at C6 of sulfoquinovose, so they are not exceptions, although their substrate range is far narrower than SsuD's and a child term "sulfoquinovose monooxygenase activity" is proposed in their gene reviews. It is not family-wide: SF4 is the only populated subfamily and also contains RutA, whose substrate is uracil, so the scope is recorded here as this subfamily with RutA excepted by name. The uncharacterized actinobacterial and fungal members of the subfamily are neither supported nor excluded; they are left without an exception entry because no evidence places them on either side, and a member-level assertion should not be manufactured from silence.
kt2440_ssue_activity FMN REDUCTASE (NADPH)
PANTHER:PTHR43408:SF1
Family 		FMN reductase (NADPH) activity
GO:0052873 		Family Supported
Family review supports GO:0052873 for PANTHER:PTHR43408:SF1. The NADPH-specific child term belongs to the SsuE group, not to the whole family. P. putida S-313 SsuE reduces FMN with NADPH and shows no detectable activity with NADH, and E. coli SsuE accepts NADPH at an efficiency comparable to NADH, which is why the E. coli annotation sits on the NAD(P)H parent GO:0008752 instead. The term must not descend into SF2: wild-type P. aeruginosa MsuE is about seventeen-fold more efficient with NADH than with NADPH, the same preference reported earlier for the P. fluorescens enzyme, and the SfnE and SfnF members of that subfamily are named as NADH-dependent reductases in the member inventory.
kt2440_ssud_activity ALKANESULFONATE MONOOXYGENASE-RELATED
PANTHER:PTHR42847:SF4
Family 		alkanesulfonate monooxygenase activity
GO:0008726 		Family Supported
Family review supports GO:0008726 for PANTHER:PTHR42847:SF4. The term holds for the SsuD orthologs of SF4, which are directly assayed in E. coli and genetically grounded in P. putida, and is defensible for MsuD, since methanesulfonate is itself an alkanesulfonate. It also holds for the sulfoquinovose monooxygenases SmoC and SquD: their reaction (RHEA:70775) is the GO:0008726 transformation applied to the primary alkyl sulfonate at C6 of sulfoquinovose, so they are not exceptions, although their substrate range is far narrower than SsuD's and a child term "sulfoquinovose monooxygenase activity" is proposed in their gene reviews. It is not family-wide: SF4 is the only populated subfamily and also contains RutA, whose substrate is uracil, so the scope is recorded here as this subfamily with RutA excepted by name. The uncharacterized actinobacterial and fungal members of the subfamily are neither supported nor excluded; they are left without an exception entry because no evidence places them on either side, and a member-level assertion should not be manufactured from silence.
s313_ssue_activity FMN REDUCTASE (NADPH)
PANTHER:PTHR43408:SF1
Family 		FMN reductase (NADPH) activity
GO:0052873 		Family Supported
Family review supports GO:0052873 for PANTHER:PTHR43408:SF1. The NADPH-specific child term belongs to the SsuE group, not to the whole family. P. putida S-313 SsuE reduces FMN with NADPH and shows no detectable activity with NADH, and E. coli SsuE accepts NADPH at an efficiency comparable to NADH, which is why the E. coli annotation sits on the NAD(P)H parent GO:0008752 instead. The term must not descend into SF2: wild-type P. aeruginosa MsuE is about seventeen-fold more efficient with NADH than with NADPH, the same preference reported earlier for the P. fluorescens enzyme, and the SfnE and SfnF members of that subfamily are named as NADH-dependent reductases in the member inventory.
s313_ssud_activity ALKANESULFONATE MONOOXYGENASE-RELATED
PANTHER:PTHR42847:SF4
Family 		alkanesulfonate monooxygenase activity
GO:0008726 		Family Supported
Family review supports GO:0008726 for PANTHER:PTHR42847:SF4. The term holds for the SsuD orthologs of SF4, which are directly assayed in E. coli and genetically grounded in P. putida, and is defensible for MsuD, since methanesulfonate is itself an alkanesulfonate. It also holds for the sulfoquinovose monooxygenases SmoC and SquD: their reaction (RHEA:70775) is the GO:0008726 transformation applied to the primary alkyl sulfonate at C6 of sulfoquinovose, so they are not exceptions, although their substrate range is far narrower than SsuD's and a child term "sulfoquinovose monooxygenase activity" is proposed in their gene reviews. It is not family-wide: SF4 is the only populated subfamily and also contains RutA, whose substrate is uracil, so the scope is recorded here as this subfamily with RutA excepted by name. The uncharacterized actinobacterial and fungal members of the subfamily are neither supported nor excluded; they are left without an exception entry because no evidence places them on either side, and a member-level assertion should not be manufactured from silence.

Gene-review completeness (15/15 grounded genes reviewed)

15 complete review(s) · 2 with deep research · 0 missing review · 13 reviewed but lacking deep research

Gene Review Complete Deep research
ssuA O85763 ✓ ✓ ✗
ssuA P75853 ✓ ✓ ✗
ssuA Q88R96 ✓ ✓ ✗
ssuB P0AAI1 ✓ ✓ ✗
ssuB Q88R93 ✓ ✓ ✓
ssuB Q8KZQ6 ✓ ✓ ✗
ssuC O85765 ✓ ✓ ✗
ssuC P75851 ✓ ✓ ✗
ssuC Q88R94 ✓ ✓ ✗
ssuD O85764 ✓ ✓ ✗
ssuD P80645 ✓ ✓ ✗
ssuD Q88R95 ✓ ✓ ✓
ssuE O85762 ✓ ✓ ✗
ssuE P80644 ✓ ✓ ✗
ssuE Q88R97 ✓ ✓ ✗

Details

Context
GammaproteobacteriaNCBITaxon:1236
Oxygen, reducing equivalents and an accepted alkanesulfonate are available; the selected proteins are expressed and functional
Canonical Ssu uptake plus reduced-flavin desulfonation implementationsMetabolic Pathwaybacterial_alkanesulfonate_uptake_desulfonation

At least one complete species-coherent canonical implementation is required. This is coverage of named transport and catalytic capabilities, not an essentiality model or a claim that five proteins alone reconstitute sulfur-dependent growth. The taxon envelope bounds sampled implementations and does not claim universal presence in Gammaproteobacteria.

alkanesulfonate catabolic processGO:0046306
Context
GammaproteobacteriaNCBITaxon:1236
Oxygen, reducing equivalents and an accepted alkanesulfonate are available; the selected proteins are expressed and functional
Variant set: Species-coherent canonical implementations by Native organism and experimentally bounded donor/substrate context (One Or More)
E. coli K-12 canonical Ssu implementationMetabolic Pathwayecoli_canonical_ssu

Native deletion/complementation and purified E. coli enzymes ground this implementation. Assay strains and expression constructs are distinguished from the K-12 sequence exemplars. Residual short-chain uptake does not make SsuABC the only route.

Context
Escherichia coli K-12NCBITaxon:83333
Aerobic sulfur-scavenging conditions with an accessible accepted alkanesulfonate

Connections

Canonical import supplies cytoplasmic alkanesulfonate for oxidative cleavage; this is pathway chaining, not a measured transporter–oxygenase physical interaction.
PMID:10781534
Deletion analysis of the Escherichia coli taurine and alkanesulfonate transport systems.
Native E. coli deletion/complementation distinguishes SsuABC and TauABC systems. It does not test interspecies subunit mixtures.
the individual components of the two transport systems were not functionally exchangeable
PMID:10480865
Characterization of a two-component alkanesulfonate monooxygenase from Escherichia coli.
Purified E. coli SsuD converts alkanesulfonate to aldehyde and sulfite. This is direct catalytic evidence for the E. coli implementation and comparative chemistry for Pseudomonas.
The pure enzyme catalyzed the conversion of pentanesulfonic acid to sulfite and pentaldehyde
PMID:10480865
Characterization of a two-component alkanesulfonate monooxygenase from Escherichia coli.
The oxygenase reaction chemically requires reduced FMN and oxygen.
SsuD catalysis was absolutely dependent on FMNH(2) and oxygen
The named SsuE partner supplies reduced FMN in this canonical implementation. Transfer may be interaction-assisted or diffusional under particular conditions; native SsuE-independent activity remains an explicit unresolved alternative.
PMID:10480865
Characterization of a two-component alkanesulfonate monooxygenase from Escherichia coli.
E. coli SsuE is the experimentally identified reduced-FMN supplier to SsuD.
SsuE is the FMN reducing enzyme providing SsuD with FMNH(2).
PMID:30171650
Not as easy as π: An insertional residue does not explain the π-helix gain-of-function in two-component FMN reductases.
SsuE and MsuE are mechanistically distinct homologous reductases; measured E. coli SsuE NADH/NADPH turnover is distinguished from S-313 extract specificity.
Exchanging the π-helix insertional residue of each enzyme did not result in equivalent kinetic properties.
PMID:10480865
Characterization of a two-component alkanesulfonate monooxygenase from Escherichia coli.
The oxygenase reaction chemically requires reduced FMN and oxygen.
SsuD catalysis was absolutely dependent on FMNH(2) and oxygen
PMID:26634408
Exposing the Alkanesulfonate Monooxygenase Protein-Protein Interaction Sites.
Interaction-assisted transfer is optimal in the tested E. coli system, while diffusion can support transfer in specified conditions.
optimal transfer of reduced flavin from SsuE to SsuD requires defined protein-protein interactions, but diffusion can occur under specified conditions.
Part 1: canonical substrate uptake
E. coli K-12 SsuABC importTransport Stepecoli_ssuabc_import

Annotons

Intact SsuABC import activity
ecoli_ssuabc_activity
Participant: Protein Complex: ATP-binding cassette (ABC) transporter complex, substrate-binding subunit-containing
Protein Complex:
ATP-binding cassette (ABC) transporter complex, substrate-binding subunit-containingGO:0055052
Active units:
ssuA subunit
Participant: Gene Product: ssuA
Gene Product:
ssuAUniProtKB:P75853
Family:
ALIPHATIC SULFONATES-BINDING PROTEIN-RELATEDPANTHER:PTHR30024:SF42
Representative Members: ssuAUniProtKB:P75853
Role: Periplasmic substrate recognition; no autonomous ATPase or translocation activity.
ssuB subunit
Participant: Gene Product: ssuB
Gene Product:
ssuBUniProtKB:P0AAI1
Family:
ALIPHATIC SULFONATES IMPORT ATP-BINDING PROTEIN SSUBPANTHER:PTHR42788:SF17
Representative Members: ssuBUniProtKB:P0AAI1
Role: ATP-hydrolysis contribution to the intact importer.
ssuC subunit
Participant: Gene Product: ssuC
Gene Product:
ssuCUniProtKB:P75851
Family:
ALIPHATIC SULFONATES TRANSPORT PERMEASE PROTEIN SSUC-RELATEDPANTHER:PTHR30151:SF38
Representative Members: ssuCUniProtKB:P75851
Role: Membrane translocation contribution to the intact importer.
Required Function:
ABC-type alkanesulfonate transporter transporter activityGO:0042959

Function

ABC-type alkanesulfonate transporter transporter activityGO:0042959
Substrates: extracellular alkanesulfonate ATP
Products: cytoplasmic alkanesulfonate ADP phosphate

Processes

alkanesulfonate transmembrane transportGO:0042918

Locations

plasma membraneGO:0005886

One species-coherent complex contributes import; no fixed oligomeric stoichiometry or cross-species hybrid activity is asserted.

PMID:10781534
Deletion analysis of the Escherichia coli taurine and alkanesulfonate transport systems.
Native E. coli deletion/complementation distinguishes SsuABC and TauABC systems. It does not test interspecies subunit mixtures.
the individual components of the two transport systems were not functionally exchangeable
Part 2: canonical reduced-FMN supply
SsuE reduced-FMN supplyReactionecoli_ssue_fmn_reduction

Annotons

SsuE FMN reduction
ecoli_ssue_activity
Participant: Gene Product: ssuE
Gene Product:
ssuEUniProtKB:P80644
Family:
FMN REDUCTASE (NADPH)PANTHER:PTHR43408:SF1
Representative Members: ssuEUniProtKB:P80644

Function

FMN reductase [NAD(P)H] activityGO:0008752
Substrates: FMN NAD(P)H
Products: reduced FMN NAD(P)+

Measured similar NADH/NADPH rates in E. coli; no transfer of S-313 donor restriction.

PMID:10480865
Characterization of a two-component alkanesulfonate monooxygenase from Escherichia coli.
E. coli SsuE is the experimentally identified reduced-FMN supplier to SsuD.
SsuE is the FMN reducing enzyme providing SsuD with FMNH(2).
PMID:30171650
Not as easy as π: An insertional residue does not explain the π-helix gain-of-function in two-component FMN reductases.
SsuE and MsuE are mechanistically distinct homologous reductases; measured E. coli SsuE NADH/NADPH turnover is distinguished from S-313 extract specificity.
Exchanging the π-helix insertional residue of each enzyme did not result in equivalent kinetic properties.
file:publications/url_https___pmc.ncbi.nlm.nih.gov_articles_PMC6295896_.md
Table 1 directly measures similar wild-type E. coli SsuE turnover with NADH and NADPH.
Wild‐type SsuE | 3.0 ± 0.1 | 57 ± 5 | 5.2 ± 0.5 | 3.7 ± 0.4 | 80 ± 20 | 5 ± 2
Part 3: oxidative desulfonation
SsuD oxidative desulfonationReactionecoli_ssud_desulfonation

Annotons

SsuD alkanesulfonate monooxygenation
ecoli_ssud_activity
Participant: Gene Product: ssuD
Gene Product:
ssuDUniProtKB:P80645
Family:
ALKANESULFONATE MONOOXYGENASE-RELATEDPANTHER:PTHR42847:SF4
Representative Members: ssuDUniProtKB:P80645

Function

alkanesulfonate monooxygenase activityGO:0008726
Substrates: alkanesulfonate reduced FMN oxygen
Products: corresponding aldehyde sulfite FMN water

Processes

alkanesulfonate catabolic processGO:0046306

C–S bond cleavage; substrate range is assay- and lineage-dependent. No claim that every sulfonate or aromatic substrate is directly accepted.

PMID:10480865
Characterization of a two-component alkanesulfonate monooxygenase from Escherichia coli.
Purified E. coli SsuD converts alkanesulfonate to aldehyde and sulfite. This is direct catalytic evidence for the E. coli implementation and comparative chemistry for Pseudomonas.
The pure enzyme catalyzed the conversion of pentanesulfonic acid to sulfite and pentaldehyde
PMID:10480865
Characterization of a two-component alkanesulfonate monooxygenase from Escherichia coli.
The oxygenase reaction chemically requires reduced FMN and oxygen.
SsuD catalysis was absolutely dependent on FMNH(2) and oxygen
P. putida KT2440 canonical Ssu implementationMetabolic Pathwaykt2440_canonical_ssu

KT2440 locus identities and family-based chemistry are corroborated by native ΔssuD and joint ΔssuBC experiments in a 2024 thesis. No isolated SsuE donor comparison or individual SsuA/B/C transport assay is asserted.

Context
Pseudomonas putida KT2440NCBITaxon:160488
Aerobic sulfur-scavenging conditions with an accessible accepted alkanesulfonate

Connections

Canonical import supplies cytoplasmic alkanesulfonate for oxidative cleavage; this is pathway chaining, not a measured transporter–oxygenase physical interaction.
file:publications/url_https___backend.orbit.dtu.dk_ws_files_406857921_PhD_Thesis_-_Garret_William_O_Connell.pdf.md
https://backend.orbit.dtu.dk/ws/files/406857921/PhD_Thesis_-_Garret_William_O_Connell.pdf
The 2024 O’Connell thesis supplies native KT2440 ΔssuD and joint ΔssuBC sulfur-utilization genetics, corroborating the locus without proving isolated B/C transport or individual A/E necessity.
Due to the genetic placement of the ssuACB enzymes (Fig S5.), only ssuCB (permease and cytoplasmic ATPase) were disrupted.
PMID:10781534
Deletion analysis of the Escherichia coli taurine and alkanesulfonate transport systems.
Native E. coli deletion/complementation distinguishes SsuABC and TauABC systems. It does not test interspecies subunit mixtures.
the individual components of the two transport systems were not functionally exchangeable
PMID:10480865
Characterization of a two-component alkanesulfonate monooxygenase from Escherichia coli.
Purified E. coli SsuD converts alkanesulfonate to aldehyde and sulfite. This is direct catalytic evidence for the E. coli implementation and comparative chemistry for Pseudomonas.
The pure enzyme catalyzed the conversion of pentanesulfonic acid to sulfite and pentaldehyde
PMID:10480865
Characterization of a two-component alkanesulfonate monooxygenase from Escherichia coli.
The oxygenase reaction chemically requires reduced FMN and oxygen.
SsuD catalysis was absolutely dependent on FMNH(2) and oxygen
file:publications/url_https___backend.orbit.dtu.dk_ws_files_406857921_PhD_Thesis_-_Garret_William_O_Connell.pdf.md
https://backend.orbit.dtu.dk/ws/files/406857921/PhD_Thesis_-_Garret_William_O_Connell.pdf
Native KT2440 ssuD deletion impairs growth on the listed tested sulfonates.
Notably, when ssuD was disrupted, growth on ethanesulfonate, bromoethanesulfonate, chloroethanesulfonate, trimethylsilipropanesulfonate, 3 -(1-pyridino)-1-propanesulfonate, HEPES, MOPS and 3 -chloro-2-hydroxy-1- propanesulfonate was negatively affected
The named SsuE partner supplies reduced FMN in this canonical implementation. Transfer may be interaction-assisted or diffusional under particular conditions; native SsuE-independent activity remains an explicit unresolved alternative.
PMID:10480865
Characterization of a two-component alkanesulfonate monooxygenase from Escherichia coli.
E. coli SsuE is the experimentally identified reduced-FMN supplier to SsuD.
SsuE is the FMN reducing enzyme providing SsuD with FMNH(2).
PMID:10480865
Characterization of a two-component alkanesulfonate monooxygenase from Escherichia coli.
The oxygenase reaction chemically requires reduced FMN and oxygen.
SsuD catalysis was absolutely dependent on FMNH(2) and oxygen
PMID:26634408
Exposing the Alkanesulfonate Monooxygenase Protein-Protein Interaction Sites.
Interaction-assisted transfer is optimal in the tested E. coli system, while diffusion can support transfer in specified conditions.
optimal transfer of reduced flavin from SsuE to SsuD requires defined protein-protein interactions, but diffusion can occur under specified conditions.
Part 1: canonical substrate uptake
P. putida KT2440 SsuABC importTransport Stepkt2440_ssuabc_import

Annotons

Intact SsuABC import activity
kt2440_ssuabc_activity
Participant: Protein Complex: ATP-binding cassette (ABC) transporter complex, substrate-binding subunit-containing
Protein Complex:
ATP-binding cassette (ABC) transporter complex, substrate-binding subunit-containingGO:0055052
Active units:
ssuA subunit
Participant: Gene Product: ssuA
Gene Product:
ssuAUniProtKB:Q88R96
Family:
ALIPHATIC SULFONATES-BINDING PROTEIN-RELATEDPANTHER:PTHR30024:SF42
Representative Members: ssuAUniProtKB:Q88R96
Role: Periplasmic substrate recognition; no autonomous ATPase or translocation activity.
ssuB subunit
Participant: Gene Product: ssuB
Gene Product:
ssuBUniProtKB:Q88R93
Family:
ALIPHATIC SULFONATES IMPORT ATP-BINDING PROTEIN SSUBPANTHER:PTHR42788:SF17
Representative Members: ssuBUniProtKB:Q88R93
Role: ATP-hydrolysis contribution to the intact importer.
ssuC subunit
Participant: Gene Product: ssuC
Gene Product:
ssuCUniProtKB:Q88R94
Family:
ALIPHATIC SULFONATES TRANSPORT PERMEASE PROTEIN SSUC-RELATEDPANTHER:PTHR30151:SF38
Representative Members: ssuCUniProtKB:Q88R94
Role: Membrane translocation contribution to the intact importer.
Required Function:
ABC-type alkanesulfonate transporter transporter activityGO:0042959

Function

ABC-type alkanesulfonate transporter transporter activityGO:0042959
Substrates: extracellular alkanesulfonate ATP
Products: cytoplasmic alkanesulfonate ADP phosphate

Processes

alkanesulfonate transmembrane transportGO:0042918

Locations

plasma membraneGO:0005886

One species-coherent complex contributes import; no fixed oligomeric stoichiometry or cross-species hybrid activity is asserted.

file:publications/url_https___backend.orbit.dtu.dk_ws_files_406857921_PhD_Thesis_-_Garret_William_O_Connell.pdf.md
https://backend.orbit.dtu.dk/ws/files/406857921/PhD_Thesis_-_Garret_William_O_Connell.pdf
The 2024 O’Connell thesis supplies native KT2440 ΔssuD and joint ΔssuBC sulfur-utilization genetics, corroborating the locus without proving isolated B/C transport or individual A/E necessity.
Due to the genetic placement of the ssuACB enzymes (Fig S5.), only ssuCB (permease and cytoplasmic ATPase) were disrupted.
PMID:10781534
Deletion analysis of the Escherichia coli taurine and alkanesulfonate transport systems.
Native E. coli deletion/complementation distinguishes SsuABC and TauABC systems. It does not test interspecies subunit mixtures.
the individual components of the two transport systems were not functionally exchangeable
Part 2: canonical reduced-FMN supply
SsuE reduced-FMN supplyReactionkt2440_ssue_fmn_reduction

Annotons

SsuE FMN reduction
kt2440_ssue_activity
Participant: Gene Product: ssuE
Gene Product:
ssuEUniProtKB:Q88R97
Family:
FMN REDUCTASE (NADPH)PANTHER:PTHR43408:SF1
Representative Members: ssuEUniProtKB:Q88R97

Function

FMN reductase (NADPH) activityGO:0052873
Substrates: FMN NADPH
Products: reduced FMN NADP+

NADPH-dependent activity inferred from SsuE classification; donor exclusivity is untested in this exact KT2440 protein.

PMID:10480865
Characterization of a two-component alkanesulfonate monooxygenase from Escherichia coli.
E. coli SsuE is the experimentally identified reduced-FMN supplier to SsuD.
SsuE is the FMN reducing enzyme providing SsuD with FMNH(2).
Part 3: oxidative desulfonation
SsuD oxidative desulfonationReactionkt2440_ssud_desulfonation

Annotons

SsuD alkanesulfonate monooxygenation
kt2440_ssud_activity
Participant: Gene Product: ssuD
Gene Product:
ssuDUniProtKB:Q88R95
Family:
ALKANESULFONATE MONOOXYGENASE-RELATEDPANTHER:PTHR42847:SF4
Representative Members: ssuDUniProtKB:Q88R95

Function

alkanesulfonate monooxygenase activityGO:0008726
Substrates: alkanesulfonate reduced FMN oxygen
Products: corresponding aldehyde sulfite FMN water

Processes

alkanesulfonate catabolic processGO:0046306

C–S bond cleavage; substrate range is assay- and lineage-dependent. No claim that every sulfonate or aromatic substrate is directly accepted.

PMID:10480865
Characterization of a two-component alkanesulfonate monooxygenase from Escherichia coli.
Purified E. coli SsuD converts alkanesulfonate to aldehyde and sulfite. This is direct catalytic evidence for the E. coli implementation and comparative chemistry for Pseudomonas.
The pure enzyme catalyzed the conversion of pentanesulfonic acid to sulfite and pentaldehyde
PMID:10480865
Characterization of a two-component alkanesulfonate monooxygenase from Escherichia coli.
The oxygenase reaction chemically requires reduced FMN and oxygen.
SsuD catalysis was absolutely dependent on FMNH(2) and oxygen
file:publications/url_https___backend.orbit.dtu.dk_ws_files_406857921_PhD_Thesis_-_Garret_William_O_Connell.pdf.md
https://backend.orbit.dtu.dk/ws/files/406857921/PhD_Thesis_-_Garret_William_O_Connell.pdf
Native KT2440 ssuD deletion impairs growth on the listed tested sulfonates.
Notably, when ssuD was disrupted, growth on ethanesulfonate, bromoethanesulfonate, chloroethanesulfonate, trimethylsilipropanesulfonate, 3 -(1-pyridino)-1-propanesulfonate, HEPES, MOPS and 3 -chloro-2-hydroxy-1- propanesulfonate was negatively affected
P. putida S-313 canonical Ssu implementationMetabolic Pathways313_canonical_ssu

AF075709 maps the exact S-313 genes; some UniProt records also merge other strains. Canonical named-component coverage is not a minimal growth genotype: SsuA and SsuE can be dispensable in tested conditions and SsuF has an additional unresolved physiological role.

Context
Pseudomonas putidaNCBITaxon:303
S-313 AF075709 native locus under the tested sulfur-scavenging conditions

Connections

Canonical import supplies cytoplasmic alkanesulfonate for oxidative cleavage; this is pathway chaining, not a measured transporter–oxygenase physical interaction.
PMID:10781557
The ssu locus plays a key role in organosulfur metabolism in Pseudomonas putida S-313.
S-313 sequence/operon analysis identifies the three ABC-transporter components. Growth genetics alone cannot establish individual-subunit necessity.
The first group consists of ssuA , ssuB , and ssuC , which are the genes for a putative ATP-binding cassette (ABC)-type transport system.
PMID:10781557
The ssu locus plays a key role in organosulfur metabolism in Pseudomonas putida S-313.
Growth without the SsuA gene in complementation constructs limits the claim that the canonical transporter is uniquely required.
Deletion of ssuA had no effect on growth with any sulfur source tested
PMID:10781557
The ssu locus plays a key role in organosulfur metabolism in Pseudomonas putida S-313.
SsuF rescue of the ssuB insertion phenotype exposes a polar-effect limit and an additional physiological requirement outside the named catalytic route.
Strain PW7 also regained the ability to utilize sulfonates as the sulfur source when provided with the ssuF gene
PMID:10781534
Deletion analysis of the Escherichia coli taurine and alkanesulfonate transport systems.
Native E. coli deletion/complementation distinguishes SsuABC and TauABC systems. It does not test interspecies subunit mixtures.
the individual components of the two transport systems were not functionally exchangeable
PMID:10480865
Characterization of a two-component alkanesulfonate monooxygenase from Escherichia coli.
Purified E. coli SsuD converts alkanesulfonate to aldehyde and sulfite. This is direct catalytic evidence for the E. coli implementation and comparative chemistry for Pseudomonas.
The pure enzyme catalyzed the conversion of pentanesulfonic acid to sulfite and pentaldehyde
PMID:10480865
Characterization of a two-component alkanesulfonate monooxygenase from Escherichia coli.
The oxygenase reaction chemically requires reduced FMN and oxygen.
SsuD catalysis was absolutely dependent on FMNH(2) and oxygen
PMID:10781557
The ssu locus plays a key role in organosulfur metabolism in Pseudomonas putida S-313.
Native S-313 complementation supports SsuD-dependent sulfonate utilization; the aliphatic substrate is pentanesulfonate.
No growth was seen with pentanesulfonate or benzenesulfonate in the absence of SsuD
The named SsuE partner supplies reduced FMN in this canonical implementation. Transfer may be interaction-assisted or diffusional under particular conditions; native SsuE-independent activity remains an explicit unresolved alternative.
PMID:10781557
The ssu locus plays a key role in organosulfur metabolism in Pseudomonas putida S-313.
The exact S-313 SsuE construct expressed in E. coli extracts has NADPH-dependent FMN reduction, some FAD activity and no detected NADH activity under the tested conditions.
SsuE revealed NADPH-dependent FMN reductase activity and lower levels of FAD reductase activity (32% of the value with FMN). No activity was observed with NADH.
PMID:10781557
The ssu locus plays a key role in organosulfur metabolism in Pseudomonas putida S-313.
SsuE-independent aliphatic-sulfonate growth demonstrates an alternative physiological route, while the reduced-FMN supplier remains unidentified.
The flavin reductase SsuE was not required for growth with aliphatic sulfonates or methionine but was needed for growth with arylsulfonates
PMID:10480865
Characterization of a two-component alkanesulfonate monooxygenase from Escherichia coli.
The oxygenase reaction chemically requires reduced FMN and oxygen.
SsuD catalysis was absolutely dependent on FMNH(2) and oxygen
PMID:26634408
Exposing the Alkanesulfonate Monooxygenase Protein-Protein Interaction Sites.
Interaction-assisted transfer is optimal in the tested E. coli system, while diffusion can support transfer in specified conditions.
optimal transfer of reduced flavin from SsuE to SsuD requires defined protein-protein interactions, but diffusion can occur under specified conditions.
Part 1: canonical substrate uptake
P. putida S-313 SsuABC importTransport Steps313_ssuabc_import

Annotons

Intact SsuABC import activity
s313_ssuabc_activity
Participant: Protein Complex: ATP-binding cassette (ABC) transporter complex, substrate-binding subunit-containing
Protein Complex:
ATP-binding cassette (ABC) transporter complex, substrate-binding subunit-containingGO:0055052
Active units:
ssuA subunit
Participant: Gene Product: ssuA
Gene Product:
ssuAUniProtKB:O85763
Family:
ALIPHATIC SULFONATES-BINDING PROTEIN-RELATEDPANTHER:PTHR30024:SF42
Representative Members: ssuAUniProtKB:O85763
Role: Periplasmic substrate recognition; no autonomous ATPase or translocation activity.
ssuB subunit
Participant: Gene Product: ssuB
Gene Product:
ssuBUniProtKB:Q8KZQ6
Family:
ALIPHATIC SULFONATES IMPORT ATP-BINDING PROTEIN SSUBPANTHER:PTHR42788:SF17
Representative Members: ssuBUniProtKB:Q8KZQ6
Role: ATP-hydrolysis contribution to the intact importer.
ssuC subunit
Participant: Gene Product: ssuC
Gene Product:
ssuCUniProtKB:O85765
Family:
ALIPHATIC SULFONATES TRANSPORT PERMEASE PROTEIN SSUC-RELATEDPANTHER:PTHR30151:SF38
Representative Members: ssuCUniProtKB:O85765
Role: Membrane translocation contribution to the intact importer.
Required Function:
ABC-type alkanesulfonate transporter transporter activityGO:0042959

Function

ABC-type alkanesulfonate transporter transporter activityGO:0042959
Substrates: extracellular alkanesulfonate ATP
Products: cytoplasmic alkanesulfonate ADP phosphate

Processes

alkanesulfonate transmembrane transportGO:0042918

Locations

plasma membraneGO:0005886

One species-coherent complex contributes import; no fixed oligomeric stoichiometry or cross-species hybrid activity is asserted.

PMID:10781557
The ssu locus plays a key role in organosulfur metabolism in Pseudomonas putida S-313.
S-313 sequence/operon analysis identifies the three ABC-transporter components. Growth genetics alone cannot establish individual-subunit necessity.
The first group consists of ssuA , ssuB , and ssuC , which are the genes for a putative ATP-binding cassette (ABC)-type transport system.
PMID:10781557
The ssu locus plays a key role in organosulfur metabolism in Pseudomonas putida S-313.
Growth without the SsuA gene in complementation constructs limits the claim that the canonical transporter is uniquely required.
Deletion of ssuA had no effect on growth with any sulfur source tested
PMID:10781557
The ssu locus plays a key role in organosulfur metabolism in Pseudomonas putida S-313.
SsuF rescue of the ssuB insertion phenotype exposes a polar-effect limit and an additional physiological requirement outside the named catalytic route.
Strain PW7 also regained the ability to utilize sulfonates as the sulfur source when provided with the ssuF gene
PMID:10781534
Deletion analysis of the Escherichia coli taurine and alkanesulfonate transport systems.
Native E. coli deletion/complementation distinguishes SsuABC and TauABC systems. It does not test interspecies subunit mixtures.
the individual components of the two transport systems were not functionally exchangeable
Part 2: canonical reduced-FMN supply
SsuE reduced-FMN supplyReactions313_ssue_fmn_reduction

Annotons

SsuE FMN reduction
s313_ssue_activity
Participant: Gene Product: ssuE
Gene Product:
ssuEUniProtKB:O85762
Family:
FMN REDUCTASE (NADPH)PANTHER:PTHR43408:SF1
Representative Members: ssuEUniProtKB:O85762

Function

FMN reductase (NADPH) activityGO:0052873
Substrates: FMN NADPH
Products: reduced FMN NADP+

Target-derived heterologous extract supports NADPH-dependent FMN reduction; NADH was not active in that assay.

PMID:10781557
The ssu locus plays a key role in organosulfur metabolism in Pseudomonas putida S-313.
The exact S-313 SsuE construct expressed in E. coli extracts has NADPH-dependent FMN reduction, some FAD activity and no detected NADH activity under the tested conditions.
SsuE revealed NADPH-dependent FMN reductase activity and lower levels of FAD reductase activity (32% of the value with FMN). No activity was observed with NADH.
PMID:10781557
The ssu locus plays a key role in organosulfur metabolism in Pseudomonas putida S-313.
SsuE-independent aliphatic-sulfonate growth demonstrates an alternative physiological route, while the reduced-FMN supplier remains unidentified.
The flavin reductase SsuE was not required for growth with aliphatic sulfonates or methionine but was needed for growth with arylsulfonates
Part 3: oxidative desulfonation
SsuD oxidative desulfonationReactions313_ssud_desulfonation

Annotons

SsuD alkanesulfonate monooxygenation
s313_ssud_activity
Participant: Gene Product: ssuD
Gene Product:
ssuDUniProtKB:O85764
Family:
ALKANESULFONATE MONOOXYGENASE-RELATEDPANTHER:PTHR42847:SF4
Representative Members: ssuDUniProtKB:O85764

Function

alkanesulfonate monooxygenase activityGO:0008726
Substrates: alkanesulfonate reduced FMN oxygen
Products: corresponding aldehyde sulfite FMN water

Processes

alkanesulfonate catabolic processGO:0046306

C–S bond cleavage; substrate range is assay- and lineage-dependent. No claim that every sulfonate or aromatic substrate is directly accepted.

PMID:10480865
Characterization of a two-component alkanesulfonate monooxygenase from Escherichia coli.
Purified E. coli SsuD converts alkanesulfonate to aldehyde and sulfite. This is direct catalytic evidence for the E. coli implementation and comparative chemistry for Pseudomonas.
The pure enzyme catalyzed the conversion of pentanesulfonic acid to sulfite and pentaldehyde
PMID:10480865
Characterization of a two-component alkanesulfonate monooxygenase from Escherichia coli.
The oxygenase reaction chemically requires reduced FMN and oxygen.
SsuD catalysis was absolutely dependent on FMNH(2) and oxygen
PMID:10781557
The ssu locus plays a key role in organosulfur metabolism in Pseudomonas putida S-313.
Native S-313 complementation supports SsuD-dependent sulfonate utilization; the aliphatic substrate is pentanesulfonate.
No growth was seen with pentanesulfonate or benzenesulfonate in the absence of SsuD