RRC ID 50577
Author Nunoura T, Chikaraishi Y, Izaki R, Suwa T, Sato T, Harada T, Mori K, Kato Y, Miyazaki M, Shimamura S, Yanagawa K, Shuto A, Ohkouchi N, Fujita N, Takaki Y, Atomi H, Takai K.
Title A primordial and reversible TCA cycle in a facultatively chemolithoautotrophic thermophile.
Journal Science
Abstract Inorganic carbon fixation is essential to sustain life on Earth, and the reductive tricarboxylic acid (rTCA) cycle is one of the most ancient carbon fixation metabolisms. A combination of genomic, enzymatic, and metabolomic analyses of a deeply branching chemolithotrophic Thermosulfidibacter takaii ABI70S6T revealed a previously unknown reversible TCA cycle whose direction was controlled by the available carbon source(s). Under a chemolithoautotrophic condition, a rTCA cycle occurred with the reverse reaction of citrate synthase (CS) and not with the adenosine 5'-triphosphate-dependent citrate cleavage reactions that had been regarded as essential for the conventional rTCA cycle. Phylometabolic evaluation suggests that the TCA cycle with reversible CS may represent an ancestral mode of the rTCA cycle and raises the possibility of a facultatively chemolithomixotrophic origin of life.
Volume 359(6375)
Pages 559-563
Published 2018-2-2
DOI 10.1126/science.aao3407
PII 359/6375/559
PMID 29420286
MeSH Bacteria / metabolism* Carbon Cycle* Chemoautotrophic Growth* Citric Acid Cycle*
IF 41.846
Times Cited 38
Resource
General Microbes JCM 13301 JCM 7687 JCM 12110 JCM 11887