Kinetics of the ancestral carbon metabolism pathways in deep-branching bacteria and archaea

Tomonari Sumi, Kouji Harada

Research output: Contribution to journalArticlepeer-review


The origin of life is believed to be chemoautotrophic, deriving all biomass components from carbon dioxide, and all energy from inorganic redox couples in the environment. The reductive tricarboxylic acid cycle (rTCA) and the Wood–Ljungdahl pathway (WL) have been recognized as the most ancient carbon fixation pathways. The rTCA of the chemolithotrophic Thermosulfidibacter takaii, which was recently demonstrated to take place via an unexpected reverse reaction of citrate synthase, was reproduced using a kinetic network model, and a competition between reductive and oxidative fluxes on rTCA due to an acetyl coenzyme A (ACOA) influx upon acetate uptake was revealed. Avoiding ACOA direct influx into rTCA from WL is, therefore, raised as a kinetically necessary condition to maintain a complete rTCA. This hypothesis was confirmed for deep-branching bacteria and archaea, and explains the kinetic factors governing elementary processes in carbon metabolism evolution from the last universal common ancestor.

Original languageEnglish
Article number149
JournalCommunications Chemistry
Issue number1
Publication statusPublished - Dec 2021

ASJC Scopus subject areas

  • Biochemistry
  • Chemistry(all)
  • Environmental Chemistry
  • Materials Chemistry


Dive into the research topics of 'Kinetics of the ancestral carbon metabolism pathways in deep-branching bacteria and archaea'. Together they form a unique fingerprint.

Cite this