ATP:cob(I)alamin adenosyltransferase CobA/CobO/ButR (IPR003724)

Short name: CblAdoTrfase_CobA

Overlapping homologous superfamilies

Family relationships



ATP:cob(I)alamin (or ATP:corrinoid) adenosyltransferases (EC:, catalyse the conversion of cobalamin (vitamin B12) into its coenzyme form, adenosylcobalamin (AdoCbl)or coenzyme B12 [PMID: 15516577]. AdoCbl contains an adenosyl moiety liganded to the cobalt ion of cobalamin via a covalent Co-C bond. AdoCbl is required as a cofactor for the activity of certain enzymes.

ATP:cob(I)alamin adenosyltransferases are classed into three groups: CobA-type [PMID: 16672609], EutT-type [PMID: 15317775] and PduO-type [PMID: 11160088]. Each of the three enzyme types appears to be specialised for particular AdoCbl-dependent enzymes or for the de novo synthesis AdoCbl. PduO and EutT are distantly related, sharing short conserved motifs, while CobA is evolutionarily unrelated and is an example of convergent evolution.

This entry represents the ATP:cob(I)alamin adenosyltransferases CobA (Salmonella typhimurium), CobO (Pseudomonas denitrificans), and ButR (Escherichia coli). There is a high degree of sequence identity between these proteins [PMID: 7916712]. CobA is a homodimer responsible for attaching the adenosyl moiety from ATP to the cobalt ion of the corrin ring, necessary for the convertion of cobalamin to adenosylcobalamin [PMID: 16672609, PMID: 15516577, PMID: 12196148, PMID: 12195810].

GO terms

Biological Process

GO:0009236 cobalamin biosynthetic process

Molecular Function

GO:0005524 ATP binding
GO:0008817 cob(I)yrinic acid a,c-diamide adenosyltransferase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.