Protein Plasticity: A Single Amino Acid Substitution in the Saccharomyces cerevisiae Oxidosqualene−Lanosterol Cyclase Generates Protosta-13(17),24-dien-3β-ol, a Rearrangement Product
journal contributionposted on 19.06.2008, 00:00 by Tung-Kung Wu, Hao-Yu Wen, Cheng-Hsiang Chang, Yuan-Ting Liu
To provide insights into the structure−function relationships of oxidosqualene−lanosterol cyclase (ERG7) from Saccharomyces cerevisiae, the Phe699 was exchanged against hydrophilic polar uncharged residues Ser, Thr, Cys, Gln, and Tyr to characterize its product profile and functional role in ERG7 activity. Among the substitutions, only the ERG7F699T mutant produced novel protosta-13(17),24-dien-3β-ol as the sole truncated rearrangement product. The results suggest that Phe699Thr mutation is likely to affect the C-17 cation stabilization during the rearrangement process.