ERG20 notes (P08524, YJL167W)

• FPP synthase, essential single-copy gene PMID:2681213; IPP+DMAPP -> GPP (EC 2.5.1.1) and GPP+IPP -> FPP (EC 2.5.1.10) [UniProt:P08524].
• Sole FPP source for non-sterol isoprenoids PMID:8096487; erg20-2 (K197E) excretes geraniol PMID:8096487.
• erg20 mutants ergosterol auxotrophs; FPPS can be rate-limiting PMID:1779710.
• Cytosol (IBA) and ER association (Kuranda 2009) PMID:19416104.
• Issues: GO:0004452 IPP isomerase IDA from PMID:7908830 is an Idi1 mutagenesis paper (same ref supports IDI1) -> UNDECIDED, flag to SGD. Vacuole NAS (Hu 2017 review, UniProt function text) lacks primary support -> MARK_AS_OVER_ANNOTATED. Ubiquinone biosynthesis RCA (HEXPPSYN-PWY-2, PWY3O-862) is superpathway inflation of a shared precursor enzyme -> MARK_AS_OVER_ANNOTATED.
• Review: 36 ACCEPT, 1 KEEP_AS_NON_CORE, 2 MODIFY, 3 MARK_AS_OVER_ANNOTATED, 1 UNDECIDED.