Vitamin B12 in the spotlight again.

Vitamin B12 in the spotlight again. Curr Opin Chem Biol. 2017 Feb 03;37:63-70 Authors: Bridwell-Rabb J, Drennan CL Abstract The ability of cobalamin to coordinate different upper axial ligands gives rise to a diversity of reactivity. Traditionally, adenosylcobalamin is associated with radical-based rearrangements, and methylcobalamin with methyl cation transfers. Recently, however, a new role for adenosylcobalamin has been discovered as a light sensor, and a methylcobalamin-dependent enzyme has been identified that is suggested to transfer a methyl anion. Additionally, recent studies have provided a wealth of new information about a third class of cobalamin-dependent enzymes that do not appear to use an upper ligand. They function in reductive dehalogenations and epoxide reduction reactions. Finally, mechanistic details are beginning to emerge about the cobalamin-dependent S-adenosylmethionine radical enzyme superfamily for which the role of cobalamin has been largely enigmatic. PMID: 28167430 [PubMed - as supplied by publisher]
Source: Current Opinion in Chemical Biology - Category: Biochemistry Authors: Tags: Curr Opin Chem Biol Source Type: research