Alginate O-acetylation

A bacterial alginate-maturation module in which the inner-membrane AlgI component supplies acetyl groups to a periplasm-facing AlgJ-AlgF relay and AlgX transfers acetyl groups to O-2 and O-3 positions of mannuronate residues in nascent alginate. Alginate precursor synthesis, polymerization, export, and mannuronate C5 epimerization are separate modules.

MODULE:alginate_o_acetylationDRAFTCONCRETEBiological Processmodules/alginate_o_acetylation.yaml
alginic acid acetylationGO:0051979
file:projects/P_PUTIDA/deep-research/PSEPK__alginate-o-acetylation__ppu00543-deep-research-openscientist.md
OpenScientist PSEPK alginate O-acetylation synthesis
Species-aware retrieval identifies the conserved AlgI-AlgJ-AlgF-AlgX machinery and excludes unrelated CysE-family enzymes.
PMID:12003941
Mutant analysis and cellular localization of the AlgI, AlgJ, and AlgF proteins required for O acetylation of alginate in Pseudomonas aeruginosa.
Defines the requirement and envelope topology of AlgI, AlgJ, and AlgF.
each mutant produced alginate lacking O-acetyl groups.
PMID:25165982
P. aeruginosa SGNH hydrolase-like proteins AlgJ and AlgX have similar topology but separate and distinct roles in alginate acetylation.
Distinguishes the AlgJ relay from the terminal, polymer-binding AlgX transferase.
AlgX binds polymannuronic acid specifically in a length-dependent manner.
PMID:31900562
Analysis of the alginate O-acetylation machinery in Pseudomonas aeruginosa.
Supports a complex containing AlgI, AlgJ, and AlgF that acts with AlgX.
Three proteins, AlgI, AlgJ and AlgF have been implicated to form a complex and act together with AlgX for O-acetylation of alginate.
UniProtKB:Q51392
Reviewed Pseudomonas aeruginosa AlgI exemplar
Provides a reviewed exemplar for the membrane acetyl-transfer component.
UniProtKB:Q51372
Reviewed Pseudomonas aeruginosa AlgX exemplar
Provides a reviewed exemplar for the terminal polymer O-acetyltransferase.

The four components are retained as distinct parts because they have separable topological and mechanistic roles. AlgI has a broad acyltransferase-family assignment, but its immediate donor and acceptor are unresolved. AlgJ has acetylesterase activity in vitro, but its physiological relay reaction is unresolved and no molecular function is asserted here; AlgF has no established catalytic activity. AlgX is the terminal O-acetyltransferase. EC 2.3.1.30 serine O-acetyltransferases are not members of this module.

5Nodes
4Parts
0Variant Sets
0Variants
4Annotons
2Connections

Derived QC

Recommended-field compliance

60.0% recommended fields populated
  • module.knowledge_gaps[0] · status (0/1)
  • module.knowledge_gaps[0] · provenance (0/1)
  • module.knowledge_gaps[1] · status (0/1)
  • module.knowledge_gaps[1].provenance[0] · reference_section_type (0/1)
  • module.knowledge_gaps[2] · status (0/1)
  • module.knowledge_gaps[2] · provenance (0/1)

Module deep research

✗ none found

No MODULE:alginate_o_acetylation 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.

Gene-review completeness (4/8 grounded genes reviewed)

4 complete review(s) · 1 with deep research · 4 missing review · 3 reviewed but lacking deep research

Gene Review Complete Deep research
algF Q88ND4 ✓ ✓ ✓
algI Q88ND2 ✓ ✓ ✗
algJ Q88ND3 ✓ ✓ ✗
algX Q88ND0 ✓ ✓ ✗
Pseudomonas aeruginosa AlgF Q06062 ✗ — —
Pseudomonas aeruginosa AlgX Q51372 ✗ — —
Pseudomonas aeruginosa AlgI Q51392 ✗ — —
Pseudomonas aeruginosa AlgJ Q51393 ✗ — —

Details

Alginate O-acetylationBiological Processalginate_o_acetylation
alginic acid acetylationGO:0051979

Connections

algI_membrane_transfer -> algJ_relay Provides Input For
algJ_relay -> algX_polymer_transfer Provides Input For
Part 1: inner-membrane acetyl-donor transfer
AlgI membrane acetyl-transfer componentReactionalgI_membrane_transfer

Annotons

AlgI membrane acyltransferase
algI_acyltransferase_activity
Participant: Family: AlgI family
Family:
AlgI familyInterPro:IPR028362
Representative Members: PSEPK AlgIUniProtKB:Q88ND2 Pseudomonas aeruginosa AlgIUniProtKB:Q51392

Function

acyltransferase activityGO:0016746

Processes

alginic acid acetylationGO:0051979

Locations

plasma membraneGO:0005886

Multi-pass membrane component that transfers an acetyl donor into the periplasm-facing relay.

Part 2: periplasm-facing acetyl relay
AlgJ SGNH-family relay componentReactionalgJ_relay

Annotons

AlgJ periplasm-facing relay protein
algJ_relay_role
Participant: Family: AlgJ family
Family:
AlgJ familyInterPro:IPR034657
Representative Members: PSEPK AlgJUniProtKB:Q88ND3 Pseudomonas aeruginosa AlgJUniProtKB:Q51393

Processes

alginic acid acetylationGO:0051979

Locations

plasma membraneGO:0005886 periplasmic spaceGO:0042597

SGNH-family component associated with the periplasmic face of the inner membrane; its exact relay chemistry remains unresolved.

Part 3: periplasmic accessory support
AlgF periplasmic accessory componentBiological ProcessalgF_accessory

Annotons

AlgF accessory protein
algF_accessory_role
Participant: Family: AlgF family
Family:
AlgF familyInterPro:IPR035422
Representative Members: PSEPK AlgFUniProtKB:Q88ND4 Pseudomonas aeruginosa AlgFUniProtKB:Q06062

Processes

alginic acid acetylationGO:0051979

Locations

periplasmic spaceGO:0042597

Non-catalytic periplasmic accessory component required for efficient operation of the AlgI-AlgJ machinery.

Part 4: terminal polymer O-acetylation
AlgX alginate O-acetyltransferaseReactionalgX_polymer_transfer

Annotons

AlgX terminal O-acetyltransferase
algX_o_acetyltransferase_activity
Participant: Family: AlgX family
Family:
AlgX familyInterPro:IPR034655
Representative Members: PSEPK AlgXUniProtKB:Q88ND0 Pseudomonas aeruginosa AlgXUniProtKB:Q51372

Function

O-acetyltransferase activityGO:0016413
Substrates: unacetylated mannuronate residues in alginate
Products: O-acetylated mannuronate residues in alginate

Processes

alginic acid acetylationGO:0051979

Locations

periplasmic spaceGO:0042597

SGNH-family enzyme that transfers acetyl groups to O-2 and O-3 positions of mannuronate residues in nascent alginate.