fabA

UniProt ID: Q88FC4
Organism: Pseudomonas putida (strain ATCC 47054 / DSM 6125 / CFBP 8728 / NCIMB 11950 / KT2440)
Review Status: DRAFT
📝 Provide Detailed Feedback

Gene Description

FabA is the bifunctional 3-hydroxyacyl-ACP dehydratase/trans-2-decenoyl-ACP isomerase of Pseudomonas putida KT2440. It contributes to general FAS-II dehydration and introduces cis unsaturation by converting the trans-2-decenoyl-ACP intermediate to cis-3-decenoyl-ACP for FabB-dependent extension.

Existing Annotations Review

GO Term Evidence Action Reason
GO:0005737 cytoplasm
IEA
GO_REF:0000120 		KEEP AS NON CORE
Summary: Cytoplasm is a plausible location recorded by UniProt but is not supported by a direct KT2440 localization experiment.
Reason: Retain the localization annotation without using it to define either catalytic core function.
Supporting Evidence:
file:PSEPK/fabA/fabA-uniprot.txt
SUBCELLULAR LOCATION: Cytoplasm
GO:0006633 fatty acid biosynthetic process
IEA
GO_REF:0000120 		ACCEPT
Summary: Correct broad pathway assignment for both FabA reactions.
Reason: Reviewed UniProt places FabA in fatty-acid biosynthesis.
Supporting Evidence:
file:PSEPK/fabA/fabA-uniprot.txt
PATHWAY: Lipid metabolism; fatty acid biosynthesis.
GO:0006636 unsaturated fatty acid biosynthetic process
IEA
GO_REF:0000104 		ACCEPT
Summary: Correct specific process assignment for FabA's isomerase branch.
Reason: Reviewed UniProt states that FabA is necessary for introducing cis unsaturation.
Supporting Evidence:
file:PSEPK/fabA/fabA-uniprot.txt
Necessary for the introduction of cis unsaturation into fatty
GO:0019171 (3R)-hydroxyacyl-[acyl-carrier-protein] dehydratase activity
IEA
GO_REF:0000120 		ACCEPT
Summary: Correct first core molecular function of bifunctional FabA.
Reason: UniProt records dehydration of (3R)-hydroxyacyl-ACP to trans-2-enoyl-ACP.
Supporting Evidence:
file:PSEPK/fabA/fabA-uniprot.txt
Reaction=a (3R)-hydroxyacyl-[ACP] = a (2E)-enoyl-[ACP] + H2O;
GO:0034017 trans-2-decenoyl-acyl-carrier-protein isomerase activity
IEA
GO_REF:0000120 		ACCEPT
Summary: Correct second core molecular function of bifunctional FabA.
Reason: UniProt records trans-2-decenoyl-ACP to cis-3-decenoyl-ACP isomerization.
Supporting Evidence:
file:PSEPK/fabA/fabA-uniprot.txt
Reaction=(2E)-decenoyl-[ACP] = (3Z)-decenoyl-[ACP];

Core Functions

Dehydrates (3R)-hydroxyacyl-ACP substrates to trans-2-enoyl-ACP during FAS-II elongation.

Molecular Function:
(3R)-hydroxyacyl-[acyl-carrier-protein] dehydratase activity
Directly Involved In:
fatty acid biosynthetic process
Supporting Evidence:
  • file:PSEPK/fabA/fabA-uniprot.txt
    Reaction=a (3R)-hydroxyacyl-[ACP] = a (2E)-enoyl-[ACP] + H2O;
  • file:PSEPK/fabA/fabA-deep-research-openscientist.md
    UniProt annotates Q88FC4 with both EC numbers and both catalytic activities under HAMAP rule MF_00405, and the bioinformatic verification (Finding 5) confirms the target protein possesses the required catalytic machinery.

Isomerizes trans-2-decenoyl-ACP to cis-3-decenoyl-ACP to initiate the anaerobic cis-unsaturated fatty-acid branch.

Molecular Function:
trans-2-decenoyl-acyl-carrier-protein isomerase activity
Directly Involved In:
unsaturated fatty acid biosynthetic process
Supporting Evidence:
  • file:PSEPK/fabA/fabA-uniprot.txt
    Reaction=(2E)-decenoyl-[ACP] = (3Z)-decenoyl-[ACP];
  • file:PSEPK/fabA/fabA-deep-research-openscientist.md
    UniProt annotates Q88FC4 with both EC numbers and both catalytic activities under HAMAP rule MF_00405, and the bioinformatic verification (Finding 5) confirms the target protein possesses the required catalytic machinery.

References

Loading supporting content…

Download this section (compressed HTML)

Suggested Questions for Experts

Q: How does KT2440 tune FabA partitioning between general dehydration and cis-isomerization?

Suggested Experiments

Experiment: Measure FabA reaction partitioning across acyl-chain lengths and temperatures and correlate it with cellular cis-unsaturated lipid content.

Deep Research

OpenScientist

(fabA-deep-research-openscientist.md)

Loading supporting content…

Download this section (compressed HTML)

📚 Additional Documentation

Notes

(fabA-notes.md)

fabA curation notes

  • Reviewed UniProt accession Q88FC4 records both FabA reactions: general
    (3R)-hydroxyacyl-ACP dehydration and trans-2-decenoyl-ACP to
    cis-3-decenoyl-ACP isomerization.
  • Both molecular functions are retained as core because they represent
    distinct required roles in FAS-II elongation and cis-unsaturated fatty-acid
    synthesis
    [file:PSEPK/fabA/fabA-uniprot.txt,
    "Reaction=(2E)-decenoyl-[ACP] = (3Z)-decenoyl-[ACP];"].
  • Cytoplasmic localization, fatty-acid biosynthesis, and unsaturated
    fatty-acid biosynthesis are accepted.

📄 View Raw YAML

Loading supporting content…

Download this section (compressed HTML)