ach1

Summary: The PTN000484586 IBA transfers a minor but experimentally observed acetyl-CoA hydrolase activity from fungal Ach1 proteins.

Reason: Acetyl-CoA hydrolysis was the historical assignment for S. cerevisiae Ach1, and the 2009 re-characterization did not abolish that activity: it found low hydrolase activity but showed that the physiologically favored reaction is succinyl-CoA:acetate CoA transfer. This IBA is therefore plausible for S. pombe ach1, which lies in PTHR43609:SF1, but the hydrolase activity should be treated as secondary to acetate CoA-transferase activity.

Summary: The EC/Rhea IEA captures an observed but minor acetyl-CoA hydrolase activity.

Reason: The RHEA:20289 and EC:3.1.2.1 mapping corresponds to the older hydrolase description of Ach1. Fleck and Brock found that S. cerevisiae Ach1p has only minor acetyl-CoA hydrolase activity relative to its succinyl-CoA:acetate CoA-transferase activity, so this broad enzymatic assertion can be retained as non-core.

Summary: Cytoplasm is a true but uninformative ancestor location for an enzyme whose specific site is the mitochondrial matrix.

Reason: Current fission-yeast GOA already contains direct HDA evidence for mitochondrion and PomBase TAS evidence for mitochondrial matrix. Budding-yeast Ach1p also fractionates mostly with mitochondria and localizes there by immunofluorescence. The UniProt SubCell cytoplasm mapping is therefore not wrong in the broad GO cellular-component graph, but should be superseded by the specific mitochondrial annotations.

Summary: Accept the high-throughput fission-yeast localization assignment to mitochondrion.

Reason: Matsuyama et al. systematically localized YFP-tagged S. pombe proteins, and PomBase curated ach1 from that data set as active in mitochondrion. This agrees with the Ascomycota PAINT placement on PTN000484602 and with direct budding-yeast fractionation and microscopy, so there is no evidence of a lineage-specific localization difference.

Summary: The PTN000484602 Ascomycota IBA assigns the conserved fungal mitochondrial localization at the right scope.

Reason: The PAINT record places mitochondrion on PTN000484602 with an Ascomycota taxon constraint, supported by S. cerevisiae, Candida albicans, and a UniProtKB fungal source. S. pombe ach1 is an ascomycete PTHR43609:SF1 member and also has an independent PomBase HDA mitochondrial annotation, so the IBA is consistent with both the family tree and target-specific localization.

Summary: The ARBA mitochondrial prediction is independently corroborated.

Reason: Although ARBA is only an electronic source, the same mitochondrial localization is supported for S. pombe by PomBase HDA evidence and for the fungal Ach1 clade by the PTN000484602 IBA. Keeping this IEA is therefore consistent with the stronger curated localization rows.

Summary: Retain the mitochondrial matrix assignment inferred by PomBase from budding-yeast Ach1p localization and enzymology.

Reason: The matrix term is consistent with Ach1's mitochondrial acetate detoxification reaction and with the S. cerevisiae localization evidence cited by PomBase. The cached paper is abstract-only, but PomBase made the TAS annotation from the full article, and independent fission-yeast HDA plus fungal PAINT rows support a mitochondrial compartment for ach1.

Summary: The PTN000484586 acetate-metabolism IBA follows from conserved succinyl-CoA:acetate CoA-transferase activity.

Reason: Fungal Ach1 proteins use acetate as the CoA acceptor in the succinyl-CoA:acetate CoA-transferase reaction, and S. cerevisiae genetics place ACH1 in acetate utilization and detoxification. S. pombe ach1 is in the same PTHR43609:SF1 subfamily and has no evidence of loss, so the broad acetate metabolic process IBA is an appropriate biological process annotation.

Summary: The InterPro2GO acetate-metabolism mapping is consistent with the Ach1 family-specific PAINT assertion.

Reason: IPR046433 is the Ach1 acetyl-CoA hydrolase/transferase entry and maps to the same acetate metabolic process supported by PTN000484586. The 2009 S. cerevisiae re-characterization identifies acetate as the CoA acceptor for Ach1p's main reaction, supporting the process term for the S. pombe family member.

Summary: Ach1's acetate CoA-transferase reaction directly forms acetyl-CoA from acetate.

Reason: PomBase inferred this biological-process term from acetate CoA-transferase activity, which is exactly the S. cerevisiae Ach1p reaction favored in vitro and invoked in mitochondrial acetate detoxification. No non-obsolete, current GO descendant is needed for the fission-yeast annotation.

Summary: Remove the ISO transfer of the human ketone-body 3-oxoacid CoA-transferase specificity.

Reason: The supported Ach1 reaction transfers CoA from succinyl-CoA to acetate, not to a 3-oxo-acid acceptor. GO:0008260 is the narrower ketone-body succinyl-CoA:3-oxo-acid CoA-transferase activity represented by the ISO donor UniProtKB:P55809, whereas the fungal PTHR43609 Ach1 node carries acetate CoA-transferase activity. This is a specificity mismatch, not merely a missing direct assay on S. pombe ach1.

Summary: Generic CoA-transferase activity is correct but superseded by the acetate-specific child term.

Reason: The N-terminal domain entry IPR003702 is detecting the same CoA-transferase family membership covered more specifically by IPR046433 and by the accepted GO:0008775 acetate CoA-transferase annotations. Because ach1's specific CoA acceptor is acetate, the parent transferase term adds no useful coverage.

Summary: The PTN000484586 acetate CoA-transferase IBA captures Ach1's primary catalytic activity.

Reason: Fleck and Brock re-characterized S. cerevisiae Ach1p as a succinyl-CoA:acetate CoA-transferase, and Candida albicans ACH1 complements the S. cerevisiae ach1 mutant. Those sources anchor the PTN000484586 PAINT node that contains S. pombe ach1 in PTHR43609:SF1, so the IBA is well-scoped.

Summary: The Ach1-specific InterPro2GO mapping agrees with the curated PAINT acetate CoA-transferase assignment.

Reason: IPR046433 is the full Ach1 family entry rather than a generic CoA-transferase domain, and its acetate CoA-transferase mapping is consistent with the accepted PTN000484586 IBA and the S. cerevisiae biochemical re-characterization.