Evolution of KaiC-Dependent Timekeepers: A Proto-circadian Timing Mechanism Confers Adaptive Fitness in the Purple Bacterium Rhodopseudomonas palustris.

ABSTRACT: Circadian (daily) rhythms are a fundamental and ubiquitous property of eukaryotic organisms. However, cyanobacteria are the only prokaryotic group for which bona fide circadian properties have been persuasively documented, even though homologs of the cyanobacterial kaiABC central clock genes are distributed widely among Eubacteria and Archaea. We report the purple non-sulfur bacterium Rhodopseudomonas palustris (that harbors homologs of kaiB and kaiC) only poorly sustains rhythmicity in constant conditions-a defining characteristic of circadian rhythms. Moreover, the biochemical characteristics of the Rhodopseudomonas homolog of the KaiC protein in vivo and in vitro are different from those of cyanobacterial KaiC. Nevertheless, R. palustris cells exhibit adaptive kaiC-dependent growth enha

SUBMITTER: Ma P 

PROVIDER: S-EPMC4794148 | biostudies-literature | 2016 Mar

REPOSITORIES: biostudies-literature