Fig 1.

DUF166 encoded by MMP_RS05055 is important for fitness during autotrophic growth. (A) The Wood-Ljungdahl pathway for CO₂ fixation, highlighted in blue, uses methyl-H₄MPT from the methanogenic pathway (left) for the methyl group of acetyl-CoA. Acetyl-CoA can be further reduced to pyruvate by pyruvate ferredoxin oxidoreductase (POR/PFOR) and reduced ferredoxin (Fd). (B) Gene neighborhood of the CODH-ACS operon. (C) Comparison of gene fitness values for growth with exogenous acetate (10 mM) compared to autotrophic growth in H₂ oxidizing conditions. Each value is the average of six autotrophic (Mc defined media) replicates and three replicates with exogenous acetate (Mc defined media + 10 mM acetate). (D) Cofitness of carbon monoxide dehydrogenase/acetyl-coenzyme synthase (CODH-ACS) subunit alpha (cdhA, MMP_RS05100) and DUF166 encoded by MMP_RS05055. Experiments identified as autotrophic conditions were performed in defined minimal media both with and without vitamins and either H₂ or formate as the electron donor.