Sterol synthesis is essential for viability in the planctomycete bacterium Gemmata obscuriglobus. Issue 3 (30th January 2019)

• Record Type: Journal Article
• Authors: Gudde, Luke R; Hulce, Martin; Largen, Alexander H; Franke, Josef D
• Is Part Of: FEMS microbiology letters. Volume 366:Issue 3(2019)
• Publication Date: 2019-01-30
• Subjects: Gemmata obscuriglobus -- oxidosqualene cyclase -- sterol synthesis -- prokaryotic evolution -- protein expression; Microbiology -- Periodicals; 579
• DOI: 10.1093/femsle/fnz019
• Languages: English
• ISSNs: 0378-1097

Abstract

ABSTRACT: Oxidosqualene cyclases (OSCs) are remarkable enzymes that catalyze the production of the first sterol, lanosterol, in sterol biosynthetic pathways. These reactions are present in a limited number of bacterial species unlike eukaryotic species where sterol synthesis is ubiquitous. The biological role(s) of OSCs, and the sterols produced by the different sterol biosynthetic pathways in bacteria, are not clearly understood. Here, we show that inhibition of the Gemmata obscuriglobus OSC enzyme resulted in the inability of cells to form colonies on solid medium and resulted in cell death within 24 hr of inactivation for planktonic cells. The inclusion of lanosterol in cell culture medium was able to rescue the cell lethality associated with the OSC inhibitors. We purified active, recombinant bacterial OSC to high levels (> 3 mg L −1 of culture) and demonstrated that the purified enzyme is active and inhibited by common OSC inhibitors. Comparable inhibitor concentrations were used in in vivo lethality experiments and in vitro enzymatic assays. Together, these results show that OSC, and the sterols produced by this enzyme, are essential for G. obscuriglobus viability. Abstract : Oxidosqualene cyclase is necessary for the viability of Gemmata obscuriglobus and functional, recombinant protein can be purified.