EC 2 - Transferases
EC 2.5 - Transferring alkyl or aryl groups, other than methyl groups
EC 2.5.1 - Transferring alkyl or aryl groups, other than methyl groups
EC 2.5.1.151 - Alkylcobalamin dealkylase
IntEnz view
ENZYME view
IntEnz Enzyme Nomenclature
EC 2.5.1.151
Names
Accepted name:
alkylcobalamin dealkylase
Systematic name:
alkylcobalamin:glutathione S-alkyltransferase
Reactions
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40719 [IUBMB]an alkylcob(III)alaminName origin: UniProt - CHECKED (C)Formula: C62H88CoN13O14PR
Charge: 0ChEBI compound status: SUBMITTED (S)apo--[alkylcobalamin reductase]GENERIC:14731Is ROOT: no
ROOT compound: GENERIC:14716Number of residues: 1glutathioneName origin: UniProt - CHECKED (C)Formula: C10H16N3O6S
Charge: -1ChEBI compound status: CHECKED (C)=an S-substituted glutathioneName origin: UniProt - CHECKED (C)Formula: C10H15N3O6SR
Charge: -1ChEBI compound status: CHECKED (C)cob(I)alamin—[alkylcobalamin reductase]GENERIC:14730Is ROOT: no
ROOT compound: GENERIC:14716Number of residues: 2 -
apo--[alkylcobalamin reductase]GENERIC:14731Is ROOT: no
ROOT compound: GENERIC:14716Number of residues: 1glutathioneName origin: UniProt - CHECKED (C)Formula: C10H16N3O6S
Charge: -1ChEBI compound status: CHECKED (C)methylcob(III)alaminName origin: UniProt - CHECKED (C)Formula: C63H91CoN13O14P
Charge: 0ChEBI compound status: CHECKED (C)=cob(I)alamin—[alkylcobalamin reductase]GENERIC:14730Is ROOT: no
ROOT compound: GENERIC:14716Number of residues: 2H+Name origin: UniProt - CHECKED (C)Formula: H
Charge: 1ChEBI compound status: CHECKED (C) -
adenosylcob(III)alaminName origin: UniProt - CHECKED (C)Formula: C72H100CoN18O17P
Charge: 0ChEBI compound status: CHECKED (C)apo--[alkylcobalamin reductase]GENERIC:14731Is ROOT: no
ROOT compound: GENERIC:14716Number of residues: 1glutathioneName origin: UniProt - CHECKED (C)Formula: C10H16N3O6S
Charge: -1ChEBI compound status: CHECKED (C)=cob(I)alamin—[alkylcobalamin reductase]GENERIC:14730Is ROOT: no
ROOT compound: GENERIC:14716Number of residues: 2H+Name origin: UniProt - CHECKED (C)Formula: H
Charge: 1ChEBI compound status: CHECKED (C)
Comments:
This mammalian enzyme, which is cytosolic, can bind internalized alkylcobalamins and process them to cob(I)alamin using the thiolate of glutathione for nucleophilic displacement. The product remains bound to the protein, and, following its oxidation to cob(II)alamin, is transferred by the enzyme, together with its interacting partner MMADHC, directly to downstream enzymes involved in adenosylcobalamin and methylcobalamin biosynthesis. In addition to its dealkylase function, the enzyme also catalyse an entirely different decyanase reaction with cyanocobalamin [cf. EC 1.16.1.6, cyanocobalamin reductase (cyanide-eliminating)].
Links to other databases
UniProtKB/Swiss-Prot:
References
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Processing of alkylcobalamins in mammalian cells: A role for the MMACHC (cblC) gene product.Mol. Genet. Metab. 97 : 260-266 (2009). [PMID: 19447654]
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A human vitamin B12 trafficking protein uses glutathione transferase activity for processing alkylcobalamins.J. Biol. Chem. 284 : 33418-33424 (2009). [PMID: 19801555]
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Structural basis of multifunctionality in a vitamin B12-processing enzyme.J. Biol. Chem. 286 : 29780-29787 (2011). [PMID: 21697092]
[EC 2.5.1.151 created 2018]