GA1 (ent-copalyl diphosphate synthase, CPS; At4g02780; UniProt Q38802) - curation notes

• Accession check: Q38802 = KSA_ARATH, gene names GA1/CPS/CPS1/ABC33, At4g02780. Fetched by accession (just fetch-gene ARATH Q38802 --alias GA1).
• Falcon deep research was attempted (just deep-research-falcon ARATH GA1) and failed (provider exit code 1); review based on cached primary literature.

Function

• First committed step of GA biosynthesis, GGPP -> ent-CPP (RHEA:14841, EC 5.5.1.13) PMID:7994182
• ga1-3 complemented by the cDNA PMID:7994182.
• Class II cyclase chemistry (DXDD general acid) PMID:20430888; GA-specific CPS have a His switch residue PMID:20430888.
• Mg2+/GGPP synergistic substrate inhibition PMID:17384166.
• Structure: active site at beta/gamma domain interface PMID:21602811.

Location

• Imported and processed in pea chloroplasts PMID:7994182; GFP targeting to chloroplasts PMID:11722763.
• Promoter active in provasculature of germinating seeds, spatially separate from late steps PMID:11737781.

Curation decisions

• terpene synthase activity (GO:0010333) and lyase activity (GO:0016829): GO places GO:0010333 under lyase activity; ent-CPP synthase (GO:0009905) is under isomerase/intramolecular lyase. Lyase REMOVED (wrong EC class); terpene synthase MODIFY -> GO:0009905.
• GA signaling TAS: over-annotation (biosynthesis is upstream of signaling).
• Mg2+ binding: non-core.