title: Alteration of the substrate's prefolded conformation and cyclization stereochemistry of oxidosqualene-lanosterol cyclase of Saccharomyces cerevisiae by substitution at phenylalanine 699.
abstract: The Saccharomyces cerevisiae ERG7(Phe699) mutants produced one chair-chair-chair (C-C-C) and two chair-boat-chair (C-B-C) truncated tricyclic compounds, one tetracyclic 17alpha-exocyclic unrearranged intermediate, and two 17beta-exocyclic truncated rearranged intermediates. These results provided direct evidence for the importance of the residue in affecting mechanistic transitions between C-B-C and C-C-C substrate conformation and between the 17alpha- and 17beta-exocyclic side chain stereochemistry as well as in stabilizing the 6-6-5 tricyclic and the protosteryl C-17 cations.
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: Cheng-Hsiang
authors.initials: CH
authors.lastname: Chang
authors.forename: Hao-Yu
authors.initials: HY
authors.lastname: Wen
authors.forename: Yuan-Ting
authors.initials: YT
authors.lastname: Liu
authors.forename: Wen-Hsuan
authors.initials: WH
authors.lastname: Li
authors.forename: Tsai-Ting
authors.initials: TT
authors.lastname: Wang
authors.forename: Wen-Shiang
authors.initials: WS
authors.lastname: Shie
mesh_terms: D000595:Amino Acid Sequence; D002384:Catalysis; D003500:Cyclization; D019751:Intramolecular Transferases / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D015394:Molecular Structure; D016297:Mutagenesis, Site-Directed; D010649:Phenylalanine / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics; D017386:Sequence Homology, Amino Acid
chemical_list: D029701:Saccharomyces cerevisiae Proteins; D010649:Phenylalanine; D019751:Intramolecular Transferases; C021924:lanosterol synthase