title: Mutation of isoleucine 705 of the oxidosqualene-lanosterol cyclase from Saccharomyces cerevisiae affects lanosterol's C/D-ring cyclization and 17α/β-exocyclic side chain stereochemistry.
abstract: Site-saturated substitution in Saccharomyces cerevisiae oxidosqualene-lanosterol cyclase at Ile705 position produced three chair-boat-chair (C-B-C) truncated tricyclic compounds, two 17α-exocyclic protosteryl intermediates, two protosteryl C-17 truncated rearranged intermediates and the normal biosynthetic product, lanosterol. These results indicated the importance of the Ile705 residue in affecting lanosterol's C/D ring stabilization including 6-6-5 tricyclic and protosteryl C-17 cations and 17α/β-exocyclic side chain stereochemistry.
authors.affiliation: Department of Biological Science and Technology, National Chiao Tung University, 300, Hsin-Chu, Taiwan, Republic of China. tkwmll@mail.nctu.edu.tw
authors.forename: Tung-Kung
authors.initials: TK
authors.lastname: Wu
authors.forename: Yi-Chun
authors.initials: YC
authors.lastname: Chang
authors.forename: Yuan-Ting
authors.initials: YT
authors.lastname: Liu
authors.forename: Cheng-Hsiang
authors.initials: CH
authors.lastname: Chang
authors.forename: Hao-Yu
authors.initials: HY
authors.lastname: Wen
authors.forename: Wen-Hsuan
authors.initials: WH
authors.lastname: Li
authors.forename: Wen-Shiang
authors.initials: WS
authors.lastname: Shie
mesh_terms: D003500:Cyclization; D019751:Intramolecular Transferases / Q000235:genetics / Q000378:metabolism*; D007532:Isoleucine / Q000235:genetics / Q000378:metabolism; D007810:Lanosterol / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D013237:Stereoisomerism; D013379:Substrate Specificity
chemical_list: D007532:Isoleucine; D007810:Lanosterol; D019751:Intramolecular Transferases; C021924:lanosterol synthase