AUTHOR=Dahlin Paul , Srivastava Vaibhav , Bulone Vincent , McKee Lauren S. TITLE=The Oxidosqualene Cyclase from the Oomycete Saprolegnia parasitica Synthesizes Lanosterol as a Single Product JOURNAL=Frontiers in Microbiology VOLUME=7 YEAR=2016 URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2016.01802 DOI=10.3389/fmicb.2016.01802 ISSN=1664-302X ABSTRACT=
The first committed step of sterol biosynthesis is the cyclisation of 2,3-oxidosqualene to form either lanosterol (LA) or cycloartenol (CA). This is catalyzed by an oxidosqualene cyclase (OSC). LA and CA are subsequently converted into various sterols by a series of enzyme reactions. The specificity of the OSC therefore determines the final composition of the end sterols of an organism. Despite the functional importance of OSCs, the determinants of their specificity are not well understood. In sterol-synthesizing oomycetes, recent bioinformatics, and metabolite analysis suggest that LA is produced. However, this catalytic activity has never been experimentally demonstrated. Here, we show that the OSC of the oomycete