Q6R7M2 · Q6R7M2_RHIFR
- ProteinMethionine synthase
- GenemetH
- StatusUniProtKB unreviewed (TrEMBL)
- Amino acids1256 (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 | 262 | Zn2+ (UniProtKB | ChEBI) | ||||
Sequence: C | ||||||
Binding site | 325 | Zn2+ (UniProtKB | ChEBI) | ||||
Sequence: C | ||||||
Binding site | 326 | Zn2+ (UniProtKB | ChEBI) | ||||
Sequence: C | ||||||
Binding site | 708 | methylcob(III)alamin (UniProtKB | ChEBI) | ||||
Sequence: E | ||||||
Binding site | 775-779 | methylcob(III)alamin (UniProtKB | ChEBI) | ||||
Sequence: GDVHD | ||||||
Binding site | 778 | Co (UniProtKB | ChEBI) of methylcob(III)alamin (UniProtKB | ChEBI); axial binding residue | ||||
Sequence: H | ||||||
Binding site | 823 | methylcob(III)alamin (UniProtKB | ChEBI) | ||||
Sequence: S | ||||||
Binding site | 827 | methylcob(III)alamin (UniProtKB | ChEBI) | ||||
Sequence: T | ||||||
Binding site | 880 | methylcob(III)alamin (UniProtKB | ChEBI) | ||||
Sequence: A | ||||||
Binding site | 967 | S-adenosyl-L-methionine (UniProtKB | ChEBI) | ||||
Sequence: D | ||||||
Binding site | 1156 | S-adenosyl-L-methionine (UniProtKB | ChEBI) | ||||
Sequence: R | ||||||
Binding site | 1211-1212 | S-adenosyl-L-methionine (UniProtKB | ChEBI) | ||||
Sequence: YF |
GO annotations
Aspect | Term | |
---|---|---|
Molecular Function | cobalamin binding | |
Molecular Function | methionine synthase activity | |
Molecular Function | zinc ion binding | |
Biological Process | methylation | |
Biological Process | pteridine-containing compound 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
- Strain
- Taxonomic lineageBacteria > Pseudomonadota > Alphaproteobacteria > Hyphomicrobiales > Rhizobiaceae > Sinorhizobium/Ensifer group > Sinorhizobium
Accessions
- Primary accessionQ6R7M2
Structure
Family & Domains
Features
Showing features for domain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Domain | 21-340 | Hcy-binding | ||||
Sequence: FRVLRQATAGRILIMDGAMGTEIQQLGLAEDHFRGDRFGGCSCHQQGNNDLLTLTQPKAIEDIHYRYAIAGADILETNTFSSTRIAQADYGMEDMVYELNRDGARLARRAAKRAEAEDGRRRFVAGALGPTNRTASISPDVNNPGYRAVTFDDLRLAYAEQVHGLIDGGADIILIETVFDTLNAKAAIFATQEIFAEKGVRLPIMISGTITDLSGRTLSGQTSEAFWYSVRHAEPFTIGLNCALGANAMRAHIDELSSVADTLICAYPNAGLPNEFGRYDESPEAMAAQIEGFARDGLVNIVGGCCGSTPDHIRAIAEAV | ||||||
Domain | 371-632 | Pterin-binding | ||||
Sequence: FVNVGERTNVTGSAKFRKLITAGDYAAALDVARDQVANGAQIIDVNMDEGLIDSKQVMVEFLNLVASEPDIARVPVMIDSSKWEVIEAGLQCVQGKALVNSISLKEGEEAFLDHARLVRAYGAAVVVMAFDEKGQADTKARKVEICTRAYRLLTENVGFPPEDIIFDPNIFAVATGIEEHNNYGVDFIEAAHEIIASLPHVHVSGGVSNLSFSFRGNEPVREAMHAVFLYHAIQAGMDMGIVNAGQLAVYDAIDPDLREACE | ||||||
Domain | 664-758 | B12-binding N-terminal | ||||
Sequence: KDLAWRQWSVEKRLEHALVNGITEFIEADTEEARRAAERPLHVIEGPLMAGMNVVGDLFGAGKMFLPQVVKSARVMKQAVAVLLPYMEVEKAANG | ||||||
Domain | 765-901 | B12-binding | ||||
Sequence: AGKILMATVKGDVHDIGKNIVGVVLACNNYEIIDLGVMVPSARILEVAREQKVDAIGLSGLITPSLDEMVHVASELEREGFDIPLLIGGATTSRVHTAVKINPRYTLGQTVYVTDASRAVGVVSSLMSPEAREAYQE | ||||||
Domain | 917-1249 | AdoMet activation | ||||
Sequence: NEAEKRRLPLSKARANAHRLDWDAYRPKTPSFLGTRVFESWDLAELARYIDWTPFFQAWELKGVYPRILADEKQGAAARQLFDDAQAMVAKIVAEKWFAPKAVVGFWPAGSIGDDIRLFTDENRRSELATLFTLRQQLAKRDGRPNVALSDFVAPAESGRGDYVGGFVVTAGIEEVALAERFERANDDYSSIMVKALADRFAEAFAERMHEYVRKELWAYAPEEAFTPEELIAEPYRGIRPAPGYPAQPDHTEKETLFRLLDAEAAIGVKLTESFAMWPGSSVSGLYIGHPDAYYFGVAKIERDQVEDYAQRKRMGVHEAERWLSPILNYVPM |
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
- Length1,256
- Mass (Da)137,930
- Last updated2004-07-05 v1
- Checksum6BBD464C980A3B70