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

In molecular biology, cob(I)yrinic acid a,c-diamide adenosyltransferase (also known as ATP:cob(I)alamin adenosyltransferase or ATP:corrinoid adenosyltransferase) EC2.5.1.17 is an enzyme which catalyses the conversion of cobalamin (vitamin B12) into one of its coenzyme forms, adenosylcobalamin (coenzyme B12, AdoCbl). 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.