|Structure (2002) 10(11):1475-87|
|Northeast Structural Genomics Consortium|
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The CbiT and CbiE enzymes participate in the biosynthesis of vitamin B12. ...
They are fused together in some organisms to form a protein called CobL, which catalyzes two methylations and one decarboxylation on a precorrin intermediate. Because CbiE has sequence homology to canonical precorrin methyltransferases, CbiT was hypothesized to catalyze the decarboxylation. We herein present the crystal structure of MT0146, the CbiT homolog from Methanobacterium thermoautotrophicum. The protein shows structural similarity to Rossmann-like S-adenosyl-methionine-dependent methyltransferases, and our 1.9 A cocrystal structure shows that it binds S-adenosyl-methionine in standard geometry near a binding pocket that could accommodate a precorrin substrate. Therefore, MT0146/CbiT probably functions as a precorrin methyltransferase and represents the first enzyme identified with this activity that does not have the canonical precorrin methyltransferase fold.
|chemistry metabolism |
|Crystallography, X-Ray Protein Structure, Tertiary Dimerization Molecular Sequence Data Promoter Regions, Genetic Methanobacterium S-Adenosylmethionine Cloning, Molecular Models, Chemical Protein Folding Binding Sites Protein Structure, Secondary Amino Acid Sequence Methyltransferases Protein Binding Sequence Homology, Amino Acid Models, Molecular |
|29 (Last update: 03/25/2017 11:57:17am)|
|Structure. 2002 Nov;10(11):1475-87.|