YAH1 (YPL252C, UniProt Q12184) – review notes

• Adrenodoxin-type [2Fe-2S] ferredoxin of the mitochondrial matrix; essential PMID:10375636. Reduced by ARH1 (NADPH) and donates electrons to several acceptors [UniProt:Q12184 "Transfers electrons from adrenodoxin reductase ARH1 to heme A synthase COX15"].
• Fe-S cluster biogenesis: PMID:10655482; PMID:12970193.
• Heme A synthesis (electron donor to Cox15): PMID:11788607.
• CoQ biosynthesis: PMID:20534343; PMID:21944752. Note GO:0120538 (C1 hydroxylase) and the Coq6 C5 hydroxylation use reduced ferredoxin as donor; Yah1 would feed Coq6 and possibly Coq4/C1 chemistry.
• GO issues:
• GO:0016653 (NAD(P)H oxidoreductase, heme protein as acceptor; IMP/IGI PMID:11788607) describes the whole Arh1-Yah1-Cox15 chain; Yah1 itself does not oxidize NAD(P)H -> MODIFY to electron transfer activity.
• GO:0140647 P450-containing electron transport chain (InterPro2GO) – S. cerevisiae has no mitochondrial P450 PMID:9727014 -> REMOVE.
• Not in YeastCyc CoQ pathways. Module uses YAH1 as representative of the mitochondrial ferredoxin electron supply (GO:0009055) – consistent.