Elucidation of the biosynthetic pathway for Okenone in Thiodictyon sp. CAD16 leads to the discovery of two novel carotene ketolases.

ABSTRACT: Okenone is a unique ketocarotenoid found in many purple sulfur bacteria; it is important because of its unique light absorption and photoprotection properties. Okenane, a compound formed by diagenetic reduction of okenone, is an important biomarker in geochemical analyses of sedimentary rocks. Despite its ecological and biogeochemical importance, the biochemical pathway for okenone synthesis has not yet been fully described. The genome sequence of an okenone-producing organism, Thiodictyon sp. strain CAD16, revealed four genes whose predicted proteins had strong sequence similarity to enzymes known to produce ψ-end group modifications of carotenoids in proteobacteria. These four genes encoded homologs of a 1,2-carotenoid hydratase (CrtC), an O-methyltransferase (CrtF), and two paralogs of

SUBMITTER: Vogl K 

PROVIDER: S-EPMC3207450 | biostudies-literature | 2011 Nov

REPOSITORIES: biostudies-literature