Abstract
Similar in their very low intracellular abundance, the metabolism of hydrogen sulfide (H2S) and vitamin B12 intersect at the sulfur mobility in PPD network where B12 serves as a cofactor, and H2S spews from enzymes with relaxed specificity. While only two mammalian enzymes require B12 for activity, cells maintain a regiment of chaperones to tailor and escort B12 from its point of entry into the cell to its targets. During this inter‐compartmental voyage, B12 is translocated between active sites in transient protein‐protein complexes, which exhibit the artful use of coordination chemistry. Structural enzymology studies on trafficking proteins are providing molecular insights into the cellular strategies for moving this portly organometallic cofactor. While the metabolic activity of gut microbiota represents a limited source of B12, it is a substantial source of H2S and necessitates adaptations by host cells to routine exposure to this respiratory toxin. Our studies are revealing the metabolic reprogramming that is part of the stress response to H2S in colon epithelial cells. Thus, although low in abundance, B12 and H2S have profound impacts on cellular biochemistry.Support or Funding InformationNational Institutes of Health (DK45776, HL58984, GM112455)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
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