A0AA96XS88 · A0AA96XS88_9PSED
- ProteinMethionine synthase
- GenemetH
- StatusUniProtKB unreviewed (TrEMBL)
- Organism
- Amino acids1236 (go to sequence)
- Protein existenceInferred from homology
- Annotation score3/5
Function
function
Catalyzes the transfer of a methyl group from methyl-cobalamin to homocysteine, yielding enzyme-bound cob(I)alamin and methionine. Subsequently, remethylates the cofactor using methyltetrahydrofolate.
Catalytic activity
- (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
Cofactor
Protein has several cofactor binding sites:
Pathway
Amino-acid biosynthesis; L-methionine biosynthesis via de novo pathway; L-methionine from L-homocysteine (MetH route): step 1/1.
Features
Showing features for binding site.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Binding site | 250 | Zn2+ (UniProtKB | ChEBI) | |||
Binding site | 313 | Zn2+ (UniProtKB | ChEBI) | |||
Binding site | 314 | Zn2+ (UniProtKB | ChEBI) | |||
Binding site | 695 | methylcob(III)alamin (UniProtKB | ChEBI) | |||
Binding site | 758-762 | methylcob(III)alamin (UniProtKB | ChEBI) | |||
Binding site | 761 | Co (UniProtKB | ChEBI) of methylcob(III)alamin (UniProtKB | ChEBI); axial binding residue | |||
Binding site | 806 | methylcob(III)alamin (UniProtKB | ChEBI) | |||
Binding site | 810 | methylcob(III)alamin (UniProtKB | ChEBI) | |||
Binding site | 863 | methylcob(III)alamin (UniProtKB | ChEBI) | |||
Binding site | 950 | S-adenosyl-L-methionine (UniProtKB | ChEBI) | |||
Binding site | 1138 | S-adenosyl-L-methionine (UniProtKB | ChEBI) | |||
Binding site | 1199-1200 | S-adenosyl-L-methionine (UniProtKB | ChEBI) | |||
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | cytosol | |
Molecular Function | cobalamin binding | |
Molecular Function | methionine synthase activity | |
Molecular Function | zinc ion binding | |
Biological Process | homocysteine metabolic process | |
Biological Process | methylation | |
Biological Process | tetrahydrofolate metabolic process |
Keywords
- Molecular function
- Biological process
- Ligand
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameMethionine synthase
- EC number
- Alternative names
Gene names
Organism names
- Organism
- Strain
- Taxonomic lineageBacteria > Pseudomonadota > Gammaproteobacteria > Pseudomonadales > Pseudomonadaceae > Pseudomonas
Accessions
- Primary accessionA0AA96XS88
Subcellular Location
UniProt Annotation
GO Annotation
Structure
Family & Domains
Features
Showing features for domain.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Domain | 8-328 | Hcy-binding | |||
Domain | 359-620 | Pterin-binding | |||
Domain | 651-745 | B12-binding N-terminal | |||
Domain | 748-884 | B12-binding | |||
Domain | 900-1236 | AdoMet activation | |||
Domain
Modular enzyme with four functionally distinct domains. The isolated Hcy-binding domain catalyzes methyl transfer from free methylcobalamin to homocysteine. The Hcy-binding domain in association with the pterin-binding domain catalyzes the methylation of cob(I)alamin by methyltetrahydrofolate and the methylation of homocysteine. The B12-binding domain binds the cofactor. The AdoMet activation domain binds S-adenosyl-L-methionine. Under aerobic conditions cob(I)alamin can be converted to inactive cob(II)alamin. Reductive methylation by S-adenosyl-L-methionine and flavodoxin regenerates methylcobalamin.
Sequence similarities
Belongs to the vitamin-B12 dependent methionine synthase family.
Keywords
- Domain
Family and domain databases
Sequence
- Sequence statusComplete
- Length1,236
- Mass (Da)135,510
- Last updated2024-03-27 v1
- Checksum36E0F6B4F3E58757
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
CP126693 EMBL· GenBank· DDBJ | WNZ76577.1 EMBL· GenBank· DDBJ | Genomic DNA |