Cob(I)yrinic acid a,c-diamide adenosyltransferase


In molecular biology, cobyrinic acid a,c-diamide adenosyltransferase is an enzyme which catalyses the conversion of cobalamin into one of its coenzyme forms, adenosylcobalamin. Adenosylcobalamin is required as a cofactor for the activity of certain enzymes. AdoCbl contains an adenosyl moiety liganded to the cobalt ion of cobalamin via a covalent Co-C bond.
ATP:cobalamin adenosyltransferases are classed into three groups: CobA-type, EutT-type and PduO-type. Each of the three enzyme types appears to be specialised for particular AdoCbl-dependent enzymes or for the de novo synthesis of AdoCbl. PduO and EutT are distantly related, sharing short conserved motifs, while CobA is evolutionarily unrelated and is an example of convergent evolution.
The CobA group includes the ATP:cobalamin adenosyltransferases CobA, CobO, and ButR. There is a high degree of sequence identity between these proteins. CobA is responsible for attaching the adenosyl moiety from ATP to the cobalt ion of the corrin ring, necessary for the conversion of cobalamin to adenosylcobalamin. PduO functions to convert cobalamin to AdoCbl for 1,2-propanediol degradation, while EutT produces AdoCbl for ethanolamine utilisation.

Synonyms

This enzyme is also known as: