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EC 2.5.1.151 - Alkylcobalamin dealkylase

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IntEnz Enzyme Nomenclature
EC 2.5.1.151

Names

Accepted name:

alkylcobalamin dealkylase

Systematic name:

alkylcobalamin:glutathione S-alkyltransferase

Reactions

40719 [IUBMB]

an alkylcob(III)alamin

Name origin: UniProt - CHECKED (C)

CHEBI:140785

Formula: C62H88CoN13O14PR
Charge: 0

ChEBI compound status: SUBMITTED (S)

apo--[alkylcobalamin reductase]

GENERIC:14731

Is ROOT: no
ROOT compound: GENERIC:14716

Number of residues: 1

an L-α amino acid residue

Name origin: UniProt - CHECKED (C)

CHEBI:83228

Formula: C2H2NOR
Charge: 0

Position: undefined

ChEBI compound status: CHECKED (C)

glutathione

Name origin: UniProt - CHECKED (C)

CHEBI:57925

Formula: C10H16N3O6S
Charge: -1

ChEBI compound status: CHECKED (C)

an S-substituted glutathione

Name origin: UniProt - CHECKED (C)

CHEBI:90779

Formula: C10H15N3O6SR
Charge: -1

ChEBI compound status: CHECKED (C)

cob(I)alamin—[alkylcobalamin reductase]

GENERIC:14730

Is ROOT: no
ROOT compound: GENERIC:14716

Number of residues: 2

cob(I)alamin

Name origin: UniProt - CHECKED (C)

CHEBI:60488

Formula: C62H88CoN13O14P
Charge: -1

Position: A

ChEBI compound status: CHECKED (C)

an L-α amino acid residue

Name origin: UniProt - CHECKED (C)

CHEBI:83228

Formula: C2H2NOR
Charge: 0

Position: B

ChEBI compound status: CHECKED (C)

H⁺

Name origin: UniProt - CHECKED (C)

CHEBI:15378

Formula: H
Charge: 1

ChEBI compound status: CHECKED (C)

63132

apo--[alkylcobalamin reductase]

GENERIC:14731

Is ROOT: no
ROOT compound: GENERIC:14716

Number of residues: 1

an L-α amino acid residue

Name origin: UniProt - CHECKED (C)

CHEBI:83228

Formula: C2H2NOR
Charge: 0

Position: undefined

ChEBI compound status: CHECKED (C)

glutathione

Name origin: UniProt - CHECKED (C)

CHEBI:57925

Formula: C10H16N3O6S
Charge: -1

ChEBI compound status: CHECKED (C)

methylcob(III)alamin

Name origin: UniProt - CHECKED (C)

CHEBI:28115

Formula: C63H91CoN13O14P
Charge: 0

ChEBI compound status: CHECKED (C)

cob(I)alamin—[alkylcobalamin reductase]

GENERIC:14730

Is ROOT: no
ROOT compound: GENERIC:14716

Number of residues: 2

cob(I)alamin

Name origin: UniProt - CHECKED (C)

CHEBI:60488

Formula: C62H88CoN13O14P
Charge: -1

Position: A

ChEBI compound status: CHECKED (C)

an L-α amino acid residue

Name origin: UniProt - CHECKED (C)

CHEBI:83228

Formula: C2H2NOR
Charge: 0

Position: B

ChEBI compound status: CHECKED (C)

H⁺

Name origin: UniProt - CHECKED (C)

CHEBI:15378

Formula: H
Charge: 1

ChEBI compound status: CHECKED (C)

S-methyl glutathione

Name origin: UniProt - CHECKED (C)

CHEBI:141467

Formula: C11H18N3O6S
Charge: -1

ChEBI compound status: CHECKED (C)

63136

adenosylcob(III)alamin

Name origin: UniProt - CHECKED (C)

CHEBI:18408

Formula: C72H100CoN18O17P
Charge: 0

ChEBI compound status: CHECKED (C)

apo--[alkylcobalamin reductase]

GENERIC:14731

Is ROOT: no
ROOT compound: GENERIC:14716

Number of residues: 1

an L-α amino acid residue

Name origin: UniProt - CHECKED (C)

CHEBI:83228

Formula: C2H2NOR
Charge: 0

Position: undefined

ChEBI compound status: CHECKED (C)

glutathione

Name origin: UniProt - CHECKED (C)

CHEBI:57925

Formula: C10H16N3O6S
Charge: -1

ChEBI compound status: CHECKED (C)

cob(I)alamin—[alkylcobalamin reductase]

GENERIC:14730

Is ROOT: no
ROOT compound: GENERIC:14716

Number of residues: 2

cob(I)alamin

Name origin: UniProt - CHECKED (C)

CHEBI:60488

Formula: C62H88CoN13O14P
Charge: -1

Position: A

ChEBI compound status: CHECKED (C)

an L-α amino acid residue

Name origin: UniProt - CHECKED (C)

CHEBI:83228

Formula: C2H2NOR
Charge: 0

Position: B

ChEBI compound status: CHECKED (C)

H⁺

Name origin: UniProt - CHECKED (C)

CHEBI:15378

Formula: H
Charge: 1

ChEBI compound status: CHECKED (C)

S-adenosylglutathione

Name origin: UniProt - CHECKED (C)

CHEBI:146184

Formula: C20H27N8O9S
Charge: -1

ChEBI compound status: SUBMITTED (S)

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

Enzymes and pathways: NC-IUBMB , BRENDA , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway

Structural data: CSA , EC2PDB

UniProtKB/Swiss-Prot:

Q5E9C8

MMAC_BOVIN

Q5ZL21

MMAC_CHICK

Q5RFU5

MMAC_DANRE

Q9Y4U1

MMAC_HUMAN

Q9CZD0

MMAC_MOUSE

References

Hannibal, L., Kim, J., Brasch, N. E., Wang, S., Rosenblatt, D. S., Banerjee, R., Jacobsen, D. W.

Processing of alkylcobalamins in mammalian cells: A role for the MMACHC (cblC) gene product.

Mol. Genet. Metab. 97 : 260-266 (2009). [PMID: 19447654]
Kim, J., Hannibal, L., Gherasim, C., Jacobsen, D. W., Banerjee, R.

A human vitamin B12 trafficking protein uses glutathione transferase activity for processing alkylcobalamins.

J. Biol. Chem. 284 : 33418-33424 (2009). [PMID: 19801555]
Koutmos, M., Gherasim, C., Smith, J. L., Banerjee, R.

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]

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

Names

Reactions

Comments:

Links to other databases

References