The cysteine 703 to isoleucine or histidine mutation of the oxidosqualene-lanosterol cyclase from Saccharomyces cerevisiae generates an iridal-type triterpenoid.
Chang CH, Chen YC, Tseng SW, Liu YT, Wen HY, Li WH, Huang CY, Ko CY, Wang TT, Wu TK. Biochimie. 2012 Nov; 94(11):2376-81. Epub 2012 Jun 23.