| Literature DB >> 15643868 |
Mamoru Yamanishi1, Tetyana Labunska, Ruma Banerjee.
Abstract
Human adenosyltransferase synthesizes coenzyme B12, for the target mitochondrial B12 enzyme, methylmalonyl-CoA mutase. It binds B12 in the "base-off" conformation in both the Co2+ and Co3+ oxidation states as revealed by UV-visible and EPR spectroscopy although it lacks the signature DXHXXG motif found in other B12 proteins that bind the cofactor in this conformation. The "base-off" conformation, which is rare at physiological pH, mirrors that in the target enzyme, methylmalonyl-CoA mutase, which utilizes the product, AdoCbl. However, the coordination environment for cobalt in the two proteins is distinct, which is reflected in an approximately 40-fold difference in their affinity for the cofactor.Entities:
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Year: 2005 PMID： 15643868 DOI： 10.1021/ja044365l
Source DB: PubMed Journal: J Am Chem Soc ISSN： 0002-7863 Impact factor: 15.419