Steroid portable pathway
Steroid pathway definition imported from the 2026-05-17 portable BLAST/HMM package.
Representative Steroid Reaction Route
Squalene to phytosterols and brassinosteroid branch. The steroid route starts from triterpenoid precursors, proceeds through squalene, 2,3-oxidosqualene, and cycloartenol, and then branches toward phytosterols and brassinosteroids; long branches are shown as curated modules.
3
curated steps/modules
Sterol Scaffold Formation
01
Substrate
Farnesyl diphosphate
C15H28O7P2
C15 prenyl-OPP
Squalene synthesis, epoxidation, and cyclization
Product
Cycloartenol
C30H50O
tetracyclic sterol nucleus with cyclopropyl side
SQS/SQE/CAS convert FPP-derived linear triterpenes into the plant sterol core.
02
Substrate
Cycloartenol-series intermediates
C28-C30 sterols
tetracyclic sterol nucleus
Demethylation, reduction, and side-chain remodeling
Product
Phytosterols
C28H48O / C29H50O
sterol nucleus-C8/C9 side chain
This segment converts cycloartenol-series intermediates into phytosterol pools such as sitosterol and campesterol.
Brassinosteroid Branch
03
Substrate
Campesterol-like sterols
C28H48O
sterol nucleus-C8 side chain
Sterol hydroxylation/oxidation to brassinosteroids
Product
Brassinosteroids
C28 oxygenated lactones
polyhydroxylated steroid lactone
DET2 and CYP90/CYP85 enzymes route campesterol-like substrates toward brassinosteroid signaling molecules.
Lineage Distribution
Assignments under this module are distributed across the following plant lineages.
