BTS1 (YPL069C, Q12051) notes

Geranylgeranyl diphosphate synthase.

• Identified as bet2-1 suppressor; encodes GGPPS PMID:7665600; null viable, cold-sensitive, reduced protein geranylgeranylation PMID:7665600.
• UniProt lists EC 2.5.1.1, 2.5.1.10 and 2.5.1.29 reactions, but only 2.5.1.29 carries evidence (PMID:7665600); kinetics given for FPP and IPP only [UniProt:Q12051 "KM=3.2 uM for farnesyl diphosphate;"]. Crystal structures with FPP/IPP sites PMID:17535895.
• Therefore GPP/FPP synthase IEA terms and the UniPathway GPP/FPP biosynthesis BPs are treated as over-annotation; FPP is made by Erg20p.
• YeastPathways places BTS1 in hexaprenyl diphosphate / ubiquinone superpathway (GGPP as Coq1 primer). No evidence bts1 cells are CoQ-deficient; ubiquinone BP marked over-annotated.
• Huh GFP HDA mitochondrion (both located_in and is_active_in) conflicts with expected cytosolic role; kept non-core.
• PMID:23493556 (EFI polyprenyl transferase survey) full text does not mention BTS1 by name in cached text; IDA accepted by deference.