Elucidation of roles for vitamin B ₁₂ in regulation of folate, ubiquinone, and methionine metabolism

Significance Using a chemical probe mimic of vitamin B 12 , we reveal a light- and B 12 -dependent DNA regulator, and make the unexpected discovery of B 12 having regulatory involvement in microbial folate, ubiquinone, and methionine processes. These findings suggest a pivotal role for B 12 in the control of cell growth, which may lead to coordination of cell behavior in complex multicellular systems. As key research questions emerge from host-associated and environmental microbiomes, we anticipate that B 12 regulatory control of metabolism will be found to be generalizable, will be critical for coordination of individual microbe and community metabolism, and that organismal interdependencies for B 12 may be pertinent to microbiome organization, stability, and overall function.