mcr1

Summary: PTN000452207 supports a broad cytochrome-b5 reductase activity at a eukaryotic node, but the NADH-specific child is already captured by the target's Rhea/EC row.

Reason: PTN000452207 places a molecular-function assertion at a broad eukaryotic node seeded by characterized S. cerevisiae MCR1 and by S. cerevisiae PGA3, a plasma-membrane-associated coenzyme-Q6 reductase in the same PTHR19370:SF143 subfamily as AIM33. The node can support only the NAD(P)H-dependent GO:0004128 parent, while A. nidulans mcr1 is separately mapped to EC 1.6.2.2 and the NADH-dependent Rhea reaction used for GO:0090524; the broad GO:0004128 claim is therefore true but entailed by the accepted NADH-specific child term for this target.

Summary: PTN000452207 places the MCR1-like subfamily in mitochondria and is consistent with the characterized mitochondrial S. cerevisiae Mcr1 ortholog.

Reason: A. nidulans mcr1 sits in PTHR19370:SF171 with S. cerevisiae MCR1, whose product is experimentally sorted to two submitochondrial compartments; PAINT placed the mitochondrion assertion at a eukaryotic node seeded by S. cerevisiae MCR1. The inferred mitochondrial outer-membrane localization on the A. nidulans UniProt record makes mitochondrion the right activity-site granularity for this IBA.

Summary: The UniProt subcellular-location transfer to the mitochondrial outer membrane matches the N-terminally anchored MCR1 family member.

Reason: The A. nidulans Swiss-Prot record infers a single-pass mitochondrial outer-membrane protein, and the S. cerevisiae ortholog has an experimentally characterized outer-membrane isoform. This is the most specific localization currently available for A. nidulans mcr1.

Summary: PTN000452208 propagates an inherited S. cerevisiae MCR1 ergosterol-biosynthesis assertion, but no A. nidulans evidence currently makes the process a core mcr1 function.

Reason: The PAINT assertion comes from an S. cerevisiae MCR1 seed and A. nidulans mcr1 is in the same MCR1-like branch, so the IBA is retained as an in-clade inherited process annotation. It is not promoted to a core A. nidulans mcr1 function here because mcr1 has not been assayed in A. nidulans, and the available CYP51 reconstitution evidence used the microsomal cytochrome-b5/NADH-cytochrome-b5-reductase system that corresponds to the ER CBR1 paralog branch rather than this mitochondrial MCR1 branch.

Summary: The ARBA/InterPro method correctly detects a pyridine nucleotide cytochrome reductase, but its oxidoreductase parent is less informative than the Rhea-supported cytochrome-b5 reductase child.

Reason: mcr1 has the conserved CBR-like domains and its UniProt record already maps the protein to the NADH:cytochrome-b5 oxidoreductase reaction. The broad GO:0016491 parent loses the electron donor and acceptor specificity and is entailed by GO:0090524 on this protein.

Summary: The Rhea/EC mapping captures the expected NADH-dependent cytochrome-b5 reductase activity for A. nidulans mcr1.

Reason: EC 1.6.2.2 and RHEA:46680 specify reduction of ferricytochrome b5 using NADH. This is the precise molecular-function term for mcr1's conserved cytochrome-b5 reductase domains and should replace the broader GO:0016491 parent term.