On the origin of biochemistry at an alkaline hydrothermal vent

A model for the origin of biochemistry at an alkaline hydrothermal vent has been developed that focuses on the acetyl-CoA (Wood-Ljungdahl) pathway of CO2 fixation and central intermediary metabolism leading to the synthesis of the constituents of purines and pyrimidines. The idea that acetogenesis and methanogenesis were the ancestral forms of energy metabolism among the first free-living eubacteria and archaebacteria, respectively, stands in the foreground. The synthesis of formyl pterins, which are essential intermediates of the Wood-Ljungdahl pathway and purine biosynthesis, is found to confront early metabolic systems with steep bioenergetic demands that would appear to link some, but not all, steps of CO2…

• NA
  National Aeronautics and Space Administration
• CI
  California Institute of Technology
• DF
  Deutsche Forschungsgemeinschaft
• JP
  Jet Propulsion Laboratory