_EC 2.1.1.13 Methionine synthase. 19 PDB entries  
EC 2.-.-.- Transferases. [17,949 PDB entries]
EC 2.1.-.- Transferring one-carbon groups. [1,711 PDB entries]
EC 2.1.1.- Methyltransferases. [1,381 PDB entries]
EC 2.1.1.13 Methionine synthase. [19 PDB entries]    
1bmt

Pathway: Methionine Synthase
Reaction: 5-methyltetrahydrofolate + L-homocysteine = tetrahydrofolate + L-methionine.
 


5-methyltetrahydrofolate
+
L-homocysteine
=
tetrahydrofolate
+
L-methionine
Molecule diagrams generated from .mol files obtained from the KEGG ftp site.

Other name(s): 5-methyltetrahydrofolate--homocysteine S-methyltransferase. 5-methyltetrahydrofolate--homocysteine transmethylase. B12 N(5)-methyltetrahydrofolate homocysteine methyltransferase. Cobalamin-dependent methionine synthase. Methionine synthase (cobalamin-dependent). Methionine synthetase. Methyltetrahydrofolate--homocysteine vitamin B12 methyltransferase. N(5)-methyltetrahydrofolate methyltransferase. N(5)-methyltetrahydrofolate--homocysteine cobalamin methyltransferase. N(5)-methyltetrahydrofolic--homocysteine vitamin B12 transmethylase.
Cofactor(s): Cob(I)alamin; Zn(2+).
 

Cob(I)alamin
Zn(2+)
Molecule diagrams generated from .mol files obtained from the KEGG ftp site.
Comments: The enzyme becomes inactivated occasionally during its cycle by oxidation of Co(I) to Co(II). Reactivation by reductive methylation is catalyzed by the enzyme itself, with S-adenosyl-L-methionine as the methyl donor and a reducing system. For the mammalian enzyme, the reducing system involves Nadph and Ec 1.16.1.8. In bacteria, the reducing agent is flavodoxin, and no further catalyst is needed (the flavodoxin is kept in the reduced state by Nadph and ec 1.18.1.2).
Links:   [IntEnz]   [ExPASy]   [KEGG]  

There are 19 PDB entries in enzyme class E.C.2.1.1.13

  PDB code Protein
1bmt
How a protein binds b12: a 3.O angstrom x-ray structure of the b12-binding domains of methionine synthase
Source: Escherichia coli. Organism_taxid: 562
Chains: A, B (246 residues) CATH domains: 1.10.1240.10 3.40.50.280
1j6r
Crystal structure of activation (adomet binding) domain of methionine synthase (tm0269) from thermotoga maritima at 2.2 a resolution
Source: Thermotoga maritima. Organism_taxid: 2336. Gene: tm0269. Expressed in: escherichia coli. Expression_system_taxid: 562.
Chains: A, B (197 residues) CATH domain: Unassigned
1k7y
E. Coli meth c-terminal fragment (649-1227)
Source: Escherichia coli. Organism_taxid: 562. Gene: escherichia coli. Expressed in: escherichia coli. Expression_system_taxid: 562.
Chain: A (577 residues) CATH domains: 3.40.50.280 3.10.196.10 1.10.1240.10 1.10.288.10
1k98
Adomet complex of meth c-terminal fragment
Source: Escherichia coli. Organism_taxid: 562. Expressed in: escherichia coli. Expression_system_taxid: 562.
Chain: A (577 residues) CATH domains: 3.40.50.280 3.10.196.10 1.10.1240.10 1.10.288.10
1msk
Methionine synthase (activation domain)
Source: Escherichia coli k12. Organism_taxid: 83333. Strain: k-12, dh5af'-p4b6.3
Chain: A (327 residues) CATH domains: 3.10.196.10 1.10.288.10
Bound ligand:   Het Group ACT is 50.00% similar to enzyme reactant L-homocysteine
1q7m
Cobalamin-dependent methionine synthase (meth) from thermotoga maritima (oxidized, monoclinic)
Source: Thermotoga maritima. Organism_taxid: 2336. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.
Chains: A, B (559 residues) CATH domains: 3.20.20.330 3.20.20.20
1q7q
Cobalamin-dependent methionine synthase (1-566) from t. Maritima (oxidized, orthorhombic)
Source: Thermotoga maritima. Organism_taxid: 2336. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.
Chains: A, B (565 residues) CATH domains: 3.20.20.330 3.20.20.20
1q7z
Cobalamin-dependent methionine synthase (1-566) from thermotoga maritima (cd2+ complex)
Source: Thermotoga maritima. Organism_taxid: 2336. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.
Chains: A, B (559 residues) CATH domains: 3.20.20.330 3.20.20.20
1q85
Cobalamin-dependent methionine synthase (1-566) from thermotoga maritima (cd2+ complex, se-met)
Source: Thermotoga maritima. Organism_taxid: 2336. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.
Chains: A, B (559 residues) CATH domains: 3.20.20.330 3.20.20.20
1q8a
Cobalamin-dependent methionine synthase (1-566) from thermotoga maritima (cd2+:l-hcy complex, se-met)
Source: Thermotoga maritima. Organism_taxid: 2336. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.
Chains: A, B (559 residues) CATH domains: 3.20.20.330 3.20.20.20
1q8j
Cobalamin-dependent methionine synthase (1-566) from thermotoga maritima (cd2+, hcy, methyltetrahydrofolate complex)
Source: Thermotoga maritima. Organism_taxid: 2336. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.
Chains: A, B (559 residues) CATH domains: 3.20.20.330 3.20.20.20
Bound ligands:   Het Group C2F is 94.00% similar to enzyme reactant 5-methyltetrahydrofolate
  Het Group HCS corresponds to enzyme reactant L-homocysteine
1y80
Structure of a corrinoid (factor iiim)-binding protein from thermoacetica
Source: Moorella thermoacetica. Organism_taxid: 1525
Chain: A (125 residues) CATH domain: 3.40.50.280
2o2k
Crystal structure of the activation domain of human methionine synthase isoform/mutant d963e/k1071n
Source: Homo sapiens. Human. Organism_taxid: 9606. Gene: mtr. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.
Chains: A, B (332 residues) CATH domains: 3.10.196.10 1.10.288.10
3bof
Cobalamin-dependent methionine synthase (1-566) from thermotoga maritima complexed with zn2+ and homocysteine
Source: Thermotoga maritima. Organism_taxid: 2336. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.
Chains: A, B (560 residues) CATH domains: 3.20.20.330 3.20.20.20
3bol
Cobalamin-dependent methionine synthase (1-566) from thermotoga maritima complexed with zn2+
Source: Thermotoga maritima. Organism_taxid: 2336. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.
Chains: A, B (557 residues) CATH domains: 3.20.20.330 3.20.20.20
3bul
E. Coli i690c/g743c meth c-terminal fragment (649-1227)
Source: Escherichia coli. Organism_taxid: 562. Gene: meth. Expressed in: escherichia coli. Expression_system_taxid: 562.
Chain: A (577 residues) CATH domains: 1.10.1240.10 3.40.50.280 3.10.196.10 1.10.288.10
3iv9
Structure of the b12-dependent methionine synthase (meth) c- half in a "his-on" conformation
Source: Escherichia coli. Organism_taxid: 562. Gene: b4019, jw3979, meth. Expressed in: escherichia coli. Expression_system_taxid: 562.
Chain: A (577 residues) CATH domains: 1.10.1240.10 3.40.50.280 3.10.196.10 1.10.288.10
3iva
Structure of the b12-dependent methionine synthase (meth) c- half with adohcy bound
Source: Escherichia coli. Organism_taxid: 562. Gene: b4019, jw3979, meth. Expressed in: escherichia coli. Expression_system_taxid: 562.
Chain: A (576 residues) CATH domains: 1.10.1240.10 3.40.50.280 3.10.196.10 1.10.288.10
4ccz
Crystal structure of human 5-methyltetrahydrofolate- homocysteine methyltransferase, the homocysteine and folate binding domains
Source: Homo sapiens. Human. Organism_taxid: 9606. Expressed in: escherichia coli. Expression_system_taxid: 469008. Expression_system_variant: r3-prare2.
Chain: A (611 residues) CATH domains: Unassigned 3.20.20.20
Bound ligand:   Het Group THG corresponds to enzyme product 5,6,7,8-tetrahydrofolate