TRI5 (Q00909, FGSG_03537) — Fusarium graminearum trichodiene synthase

Identity

• Trichodiene synthase, EC 4.2.3.6, RHEA:12052; Pfam PF06330 (TRI5); UniProt: "catalyzes the isomerization and cyclization of farnesyl pyro-phosphate to form trichodiene, the first cyclic intermediate in the biosynthetic pathway for trichothecenes".
• Deep research: genes/GIBZE/TRI5/TRI5-deep-research-falcon.md (Edison/falcon).

Molecular function

• PMID:30664933
• Recombinant enzyme: PMID:30664933
• Non-catalytic role: PMID:30664933 The proposed physical interaction with ER-anchored TRI1/TRI4/TRI11 is a model only.

Location

• PMID:30664933

Pathway / virulence (indirect)

• PMID:8589414
• PMID:18179606 Fully pathogenic on Arabidopsis floral tissue.
• PMID:20507460 Host- and chemotype-dependent.
• PMID:38877764
• Virulence is a property of DON (ribosome inhibitor acting in host cells), not of the TRI5 protein: necessity, not participation. No host-interaction BP term proposed.

GO term checks (QuickGO, 2026-10-02)

• No "trichothecene biosynthetic process" term; GO:0106110 vomitoxin biosynthetic process (DON) exists, is_a descendant of GO:0016106 sesquiterpenoid biosynthetic process and GO:0043386 mycotoxin biosynthetic process.
• Comparator: GO:0106110 has a single annotation in GOA — to the TRI5 gene product under accession A0A1I9FCV5 (FG03537.1, TAS, PMID:38877764). So curators already apply this term to TRI5; used as MODIFY replacement for the InterPro IEA.

Decisions

• GO:0016106 IEA -> MODIFY to GO:0106110.
• GO:0016838 IEA -> ACCEPT (correct EC 4.2.3 parent).
• GO:0045482 IEA, IMP -> ACCEPT.
• NEW GO:0005829 cytosol (TAS, PMID:30664933).