Summary: Rhea-mapping IEA from RHEA:31891 (1-phenyl-1,2-propanedione reduction); the most informative existing MF term for this broad-specificity NADPH carbonyl reductase.

Reason: The protein reduces aryl alpha-diketones (benzil, 1-phenyl-1,2-propanedione) to secondary alcohols with NADPH. That is the reaction class of GO:0004090 (EC 1.1.1.184). The physiological substrate is unknown, which is consistent with this broad term rather than a substrate-specific one.

Summary: Genome-wide GFP localization places Irc24 in the cytoplasm.

Reason: Consistent with a soluble SDR without targeting signals; supported for the paralog Nre1 by the same high-throughput datasets.

Summary: No biological process is established.

Reason: The only process-level data are an increased-Rad52-foci deletion phenotype (a screen hit with no mechanism) and benzil reduction, a non-physiological reaction. ND is the honest statement. IRC24-notes.md weighs the two process-level hints in this species (Rad52 foci on deletion, PMID:18085829; induction by DNA damage, PMID:17163986) and finds that neither identifies a biological process.

Summary: In vitro NADPH-dependent reduction of benzil to (S)-benzoin by recombinant YIR036C.

Reason: The assay (NADPH-dependent reduction of the diketone benzil to the secondary alcohol (S)-benzoin) is sound, but GO:0016616 is the EC 1.1.1.- grouping class and says only that some CH-OH/NAD(P) oxidoreduction occurs. The specific term GO:0102306 benzil reductase [(S)-benzoin-forming] activity was obsoleted (go-ontology#30498) because benzil is not a physiological substrate, and annotations were moved up to this grouping term. The reaction is, however, an instance of GO:0004090 carbonyl reductase (NADPH) activity (a secondary alcohol + NADP+ = a ketone + NADPH + H+; EC 1.1.1.184, whose synonyms explicitly include xenobiotic ketone reductase). GO already maps the sister EC 1.1.1.320 reaction RHEA:31891 (1-phenyl-1,2-propanedione) to GO:0004090. GO:0004090 is the informative term that respects the obsoletion decision; no new benzil-specific term is warranted.

Proposed replacements: carbonyl reductase (NADPH) activity

Summary: Purified His-tagged Irc24 reduces benzil with NADPH (preferred) or NADH.

Reason: The assay (NADPH-dependent reduction of the diketone benzil to the secondary alcohol (S)-benzoin) is sound, but GO:0016616 is the EC 1.1.1.- grouping class and says only that some CH-OH/NAD(P) oxidoreduction occurs. The specific term GO:0102306 benzil reductase [(S)-benzoin-forming] activity was obsoleted (go-ontology#30498) because benzil is not a physiological substrate, and annotations were moved up to this grouping term. The reaction is, however, an instance of GO:0004090 carbonyl reductase (NADPH) activity (a secondary alcohol + NADP+ = a ketone + NADPH + H+; EC 1.1.1.184, whose synonyms explicitly include xenobiotic ketone reductase). GO already maps the sister EC 1.1.1.320 reaction RHEA:31891 (1-phenyl-1,2-propanedione) to GO:0004090. GO:0004090 is the informative term that respects the obsoletion decision; no new benzil-specific term is warranted.

Proposed replacements: carbonyl reductase (NADPH) activity

Summary: Combined IEA driven by RHEA:25968 mapped to the EC 1.1.1.- grouping class.

Reason: This IEA is generated from the RHEA:25968 narrowMatch xref on the grouping class GO:0016616, which was added when GO:0102306 was obsoleted. It is not wrong, but it is uninformative; a RHEA reaction mapped to an EC-incomplete grouping class yields annotations that say nothing about substrate class. Replace with GO:0004090 (and fix the xref upstream: RHEA:25968 should be a narrowMatch of GO:0004090, as its sister reaction RHEA:31891 already is).

Proposed replacements: carbonyl reductase (NADPH) activity

Summary: IBA to an NAD(P)H oxidase (O2 acceptor) class, seeded by IRC24's own IDA.

Reason: This IBA inherits from PTN002453021, which is seeded by the IRC24 IDA (SGD:S000001475) to GO:0050664. That seed annotation used a term whose acceptor (O2) does not match the benzil reductase assay, so the propagated term is wrong for the same reason. The underlying inherited function (an NADPH-dependent carbonyl reductase shared by the IRC24/NRE1 paralogs) is sound and is better expressed as GO:0004090.

Proposed replacements: carbonyl reductase (NADPH) activity

Summary: Benzil reductase assay annotated to an NAD(P)H:O2 oxidoreductase term.

Reason: GO:0050664 (EC 1.6.3.-) describes NAD(P)H oxidation with molecular oxygen as the electron acceptor (NAD(P)H oxidases). The benzil reductase assay measures NADPH consumption coupled to reduction of an organic diketone; O2 is not the acceptor. The experimental observation is correct, but the term does not describe it. The correct term is GO:0004090 carbonyl reductase (NADPH) activity.

Proposed replacements: carbonyl reductase (NADPH) activity