Convergent evolution of a modified, acetate-driven TCA cycle in bacteria
Waldan K Kwong1, Hao Zheng1, Nancy A Moran1
1Department of Integrative Biology, University of Texas at Austin, Austin, Texas 78712, USA.
Abstract:
The tricarboxylic acid (TCA) cycle is central to energy production and biosynthetic precursor synthesis in aerobic organisms. There are few known variations of a complete TCA cycle, with the common notion being that the enzymes involved have already evolved towards optimal performance. Here, we present evidence that an alternative TCA cycle, in which acetate:succinate CoA-transferase (ASCT) replaces the enzymatic step typically performed by succinyl-CoA synthetase (SCS), has arisen in diverse bacterial groups, including microbial symbionts of animals such as humans and insects.
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