Download MendeleyCrystal structure of precorrin-8x methyl mutase.
Shipman, L.W., Li, D., Roessner, C.A., Scott, A.I., Sacchettini, J.C.(2001) Structure 9: 587-596
- PubMed: 11470433
- DOI: https://doi.org/10.1016/s0969-2126(01)00618-9
- Primary Citation of Related Structures:
1F2V, 1I1H - PubMed Abstract:
The crystal structure of precorrin-8x methyl mutase (CobH), an enzyme of the aerobic pathway to vitamin B12, provides evidence that the mechanism for methyl migration can plausibly be regarded as an allowed [1,5]-sigmatropic shift of a methyl group from C-11 to C-12 at the C ring of precorrin-8x to afford hydrogenobyrinic acid. The dimeric structure of CobH creates a set of shared active sites that readily discriminate between different tautomers of precorrin-8x and select a discrete tautomer for sigmatropic rearrangement. The active site contains a strictly conserved histidine residue close to the site of methyl migration in ring C of the substrate. Analysis of the structure with bound product suggests that the [1,5]-sigmatropic shift proceeds by protonation of the ring C nitrogen, leading to subsequent methyl migration.
Organizational Affiliation:
Department of Chemistry, Texas A&M University, College Station, TX 77843, USA. sacchett@tamu.edu
