Methylmalonyl-CoA Mutase with B12 Coenzyme from the Protein Data Base

Methylmalonyl-CoA Mutase with B12 Coenzyme

Entry retrieved from the Protein Data Bank at RCSB.

1REQ: Isomerase. Date: Jan 19, 1996.
Title: Methylmalonyl-CoA Mutase
Authors: F.Mancia, N.H.Keep, A.Nakagawa, P.F.Leadlay, S.Mcsweeney, B.Rasmussen, P.Bosecke, O.Diat, P.R.Evans
Compound: Methylmalonyl-Coa Mutase Ec: 5.4.99.2 Desulpho-Coa, And A Glycerol In The Active Site. B12 Is Present Largely As Reduced Cob(II)Alamin, Or B12r.
Source: Propionibacterium Freudenreichii Subsp. Shermanii.
Method: X-Ray Diffraction. Resolution 2.0 Ang.
Ligands: B12 cobalamin, DCA (desulfo coenzyme A), GOL (glycerol).

The oxidized form of coenzyme B₁₂ contains Co(III) coordinated by the adenosyl group. The adenosylcobalamin Ad-CH₂-Co(III) serves as a H radical acceptor by way of forming Ad-CH₃ + Co(II). It is the radical thus formed by the substrate which will then undergo 1,2-shift followed by H-radical transfer. See the text by Bruice on page 1017 for details.

Figure. The X-ray structure of methylmalonyl-CoA mutase. Only the cofactors are shown: Reduced forms of B₁₂, desulfo coenzyme A, and glycerol.