The cysteine 703 to isoleucine or histidine mutation of the oxidosqualene-lanosterol cyclase from Saccharomyces cerevisiae generates an iridal-type triterpenoid.
The Cys703 to Ile or His mutation within Saccharomyces cerevisiae oxidosqualene-lanosterol cyclase ERG7 (ERG7(C703I/H)) generates an unusual truncated bicyclic rearranged intermediate, (8R,9R,10R)-polypoda-5,13E,17E,21-tetraen-3β-ol, related to iridal-skeleton triterpenoid. Numerous oxidosqualene-cyclized truncated intermediates, including tricyclic, unrearranged tetracyclic with 17α/β exocyclic hydrocarbon side chain, rearranged tetracyclic, and chair-chair-chair tricyclic intermediates (compounds 3-9), were also isolated from the ERG7(C703X) site-saturated mutations or the ERG7(F699T/C703I) double mutation, indicating the functional role of the Cys703 residue in stabilizing the bicyclic C-8 cation and the rearranged intermediate or interacting with Phe699, and opened a new avenue of engineering ERG7 for producing biological active agents.
Department of Biological Science and Technology, National Chiao Tung University, 300 Hsin-Chu, Taiwan.
Cheng-Hsiang
CH
Chang
Yi-Chi
YC
Chen
Sheng-Wei
SW
Tseng
Yuan-Ting
YT
Liu
Hao-Yu
HY
Wen
Wen-Hsuan
WH
Li
Chiao-Ying
CY
Huang
Cheng-Yu
CY
Ko
Tsai-Ting
TT
Wang
Tung-Kung
TK
Wu
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D055162:Biocatalysis; D003545:Cysteine; D006639:Histidine; D019751:Intramolecular Transferases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D007532:Isoleucine; D008958:Models, Molecular; D009154:Mutation; D011487:Protein Conformation; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000378:metabolism; D014315:Triterpenes / Q000378:metabolism*
D014315:Triterpenes; C473636:iridal; D007532:Isoleucine; D006639:Histidine; D019751:Intramolecular Transferases; C021924:lanosterol synthase; D003545:Cysteine