wA encodes the polyketide synthase responsible for the first step of conidial green-pigment biosynthesis in Aspergillus nidulans. wA produces the naphthopyrone (YWA1) precursor of the conidial pigment; wA mutants form colorless (white) conidia. The pigment is subsequently modified by downstream enzymes including the conidial laccase yA to yield the mature green color.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0016491 oxidoreductase activity | IBA GO_REF:0000033 | MARK AS OVER ANNOTATED | Summary: Imprecise MF: wA is a polyketide synthase; a generic oxidoreductase term does not capture its activity. Reason: wA is homologous to polyketide and fatty acid synthases and performs polyketide synthesis; the IBA 'oxidoreductase activity' is an imprecise propagation. Proposed replacements: polyketide synthase activity |
| GO:0004315 3-oxoacyl-[acyl-carrier-protein] synthase activity | IEA GO_REF:0000002 | ACCEPT | Summary: Accept: 3-oxoacyl-[acyl-carrier-protein] synthase activity. Reason: The ketosynthase domain of the WA polyketide synthase. The term names the condensation step of polyketide chain extension, which is the catalytic core of the megasynthase. |
| GO:0006633 fatty acid biosynthetic process | IEA GO_REF:0000002 | MARK AS OVER ANNOTATED | Summary: Over-annotated: wA makes a polyketide pigment, not fatty acids. Reason: Propagated from fatty-acid-synthase homology; wA synthesizes the naphthopyrone pigment precursor, not fatty acids. Proposed replacements: pigment biosynthetic process |
| GO:0016740 transferase activity | IEA GO_REF:0000002 | KEEP AS NON CORE | Summary: Generic transferase-activity term. Reason: Root-level electronic term; uninformative for the PKS. |
| GO:0016746 acyltransferase activity | IEA GO_REF:0000002 | ACCEPT | Summary: Accept: acyltransferase activity. Reason: The acyltransferase domain that loads extender units onto the carrier protein; a constituent activity of the same megasynthase rather than an independent function. |
| GO:0031177 phosphopantetheine binding | IEA GO_REF:0000002 | ACCEPT | Summary: Accept: phosphopantetheine binding. Reason: The phosphopantetheine attachment site of the acyl-carrier domain. A cofactor/structural facet of the WA polyketide synthase, not a separate biological role. |
| GO:0046148 pigment biosynthetic process | IEA GO_REF:0000117 | ACCEPT | Summary: Accept: pigment biosynthetic process. Reason: WA produces the polyketide precursor of the conidial green pigment, so a pigment-biosynthesis process term is correct; the developmental-pigmentation term below is the more specific statement. |
| GO:0019748 secondary metabolic process | NAS PMID:22228366 Advances in Aspergillus secondary metabolite research in the... | ACCEPT | Summary: Accept: secondary metabolic process. Reason: Author statement in a review of Aspergillus secondary metabolism. Correct in that a polyketide product is a secondary metabolite, but NAS from a review article is the weakest evidence line here and the term is very general. |
| GO:0052716 hydroquinone:oxygen oxidoreductase activity | IMP PMID:7050088 Purification and characterization of the conidial laccase of... | REMOVE | Summary: Mis-attributed: laccase (hydroquinone:oxygen oxidoreductase) activity is that of the conidial laccase yA, not the PKS wA, and is contradicted by the cited paper itself. Reason: The cited paper (PMID:7050088) purifies the conidial laccase and states that laccase activity is absent "in a strain carrying a mutation in the structural gene for laccase" (yA), and that wA strains lack the laccase's substrate (the wA-derived pigment precursor) - i.e. wA supplies the substrate and is upstream of the laccase, it is not the laccase. Combined with wA being a polyketide synthase (PMID:1465094), the GO:0052716 activity is a wrong-enzyme cross-attribution to wA, not merely an over-broad annotation. This is a genuinely contradicted molecular function (the cited evidence refutes it), so REMOVE rather than MARK_AS_OVER_ANNOTATED. Supporting Evidence: PMID:7050088 Since wA strains lack the precursor of the wild-type green pigment, i.e., the laccase substrate |
| GO:0043324 pigment metabolic process involved in developmental pigmentation | IMP PMID:4624671 Absence of laccase from yellow-spored mutants of Aspergillus... | ACCEPT | Summary: Accept: pigment metabolic process involved in developmental pigmentation. Reason: The most informative process term in this set: the classic spore-colour mutant series ties the WA polyketide product specifically to conidial pigmentation rather than to secondary metabolism at large. |
| GO:0046148 pigment biosynthetic process | IMP PMID:1465094 The developmentally regulated Aspergillus nidulans wA gene e... | ACCEPT | Summary: Core process. wA is required for conidial pigment biosynthesis. Reason: wA is required for green-pigment synthesis; wA mutants have white conidia. Supporting Evidence: PMID:1465094 The Aspergillus nidulans wA gene is required for synthesis of a green pigment present in the walls of mature asexual spores (conidia); wA mutants produce colorless (white) conidia |
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