EC - Precorrin-8X methylmutase

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IntEnz Enzyme Nomenclature


Accepted name:
precorrin-8X methylmutase
Other names:
hydrogenobyrinic acid-binding protein
precorrin isomerase
HBA synthase
cobH (gene name)
Systematic name:
precorrin-8X 11,12-methylmutase



The enzyme, which participates in the aerobic (late cobalt insertion) adenosylcobalamin biosynthesis pathway, catalyses the conversion of precorrin-8X to hydrogenobyrinate by methyl rearrangement. The equivalent enzyme in the anaerobic pathway is EC Formerly EC

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Structural data: CSA , EC2PDB
Gene Ontology: GO:0016993


  1. Thibaut, D., Couder, M., Famechon, A., Debussche, L., Cameron, B., Crouzet, J., Blanche, F.
    The final step in the biosynthesis of hydrogenobyrinic acid is catalyzed by the cobH gene product with precorrin-8X as the substrate.
    J. Bacteriol. 174 : 1043-1049 (1992). [PMID: 1732194]
  2. Crouzet, J., Cameron, B., Cauchois, L., Rigault, S., Rouyez, M.C., Blanche, F., Thibaut, D., Debussche, L.
    Genetic and sequence analysis of an 8.7-kilobase Pseudomonas denitrificans fragment carrying eight genes involved in transformation of precorrin-2 to cobyrinic acid.
    J. Bacteriol. 172 : 5980-5990 (1990). [PMID: 2211521]
  3. Shipman, L. W., Li, D., Roessner, C. A., Scott, A. I., Sacchettini, J. C.
    Crystal structure of precorrin-8x methyl mutase.
    Structure 9 : 587-596 (2001). [PMID: 11470433]

[EC created 1999 as EC, transferred 2014 to EC]