P07989 · T1M_SALPO
- ProteinType I restriction enzyme StySPI methylase subunit
- GenehsdM
- StatusUniProtKB reviewed (Swiss-Prot)
- Organism
- Amino acids529 (go to sequence)
- Protein existenceInferred from homology
- Annotation score3/5
Function
function
The subtype gamma methyltransferase (M) subunit of a type I restriction enzyme. The M and S subunits together form a methyltransferase (MTase) that methylates A-2 on the top strand and A-3 on the bottom strand of the sequence 5'-AACN6GTRC-3'. In the presence of the R subunit the complex can also act as an endonuclease, binding to the same target sequence but cutting the DNA some distance from this site. Whether the DNA is cut or modified depends on the methylation state of the target sequence. When the target site is unmodified, the DNA is cut. When the target site is hemimethylated, the complex acts as a maintenance MTase modifying the DNA so that both strands become methylated (PubMed:12654995, PubMed:3025838).
After locating a non-methylated recognition site, the enzyme complex serves as a molecular motor that translocates DNA in an ATP-dependent manner until a collision occurs that triggers cleavage (By similarity).
After locating a non-methylated recognition site, the enzyme complex serves as a molecular motor that translocates DNA in an ATP-dependent manner until a collision occurs that triggers cleavage (By similarity).
Miscellaneous
Type I restriction and modification enzymes are complex, multifunctional systems which require ATP, S-adenosyl methionine and Mg2+ as cofactors and, in addition to their endonucleolytic and methylase activities, are potent DNA-dependent ATPases.
Catalytic activity
- a 2'-deoxyadenosine in DNA + S-adenosyl-L-methionine = an N6-methyl-2'-deoxyadenosine in DNA + H+ + S-adenosyl-L-homocysteine
Features
Showing features for binding site.
GO annotations
Aspect | Term | |
---|---|---|
Molecular Function | DNA binding | |
Molecular Function | N-methyltransferase activity | |
Molecular Function | site-specific DNA-methyltransferase (adenine-specific) activity | |
Biological Process | DNA restriction-modification system | |
Biological Process | methylation |
Keywords
- Molecular function
- Biological process
- Ligand
Enzyme and pathway databases
Protein family/group databases
Names & Taxonomy
Protein names
- Recommended nameType I restriction enzyme StySPI methylase subunit
- EC number
- Short namesM protein
- Alternative names
Gene names
Organism names
- Organism
- Taxonomic lineageBacteria > Pseudomonadota > Gammaproteobacteria > Enterobacterales > Enterobacteriaceae > Salmonella
Accessions
- Primary accessionP07989
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000088025 | 1-529 | Type I restriction enzyme StySPI methylase subunit | |||
Sequence: MNNNDLVAKLWKLCDNLRDGGVSYQNYVNELASLLFLKMCKETGQEADYLPEGYRWDDLKSRIGQEQLQFYRNLLVHLGADEKKLVQAVFQNVNTTITQPKQLTELVSSMDSLDWYNGDHGKSRDDFGDMYEGLLQKNANETKSGAGQYFTPRPLIKTIIHLLKPQPREVVQDPAAGTAGFLIEADRYVKSQTNDLDDLDGDAQDFQIKKAFVGLELVPGTRRLALMNCLLHDIEGNLDHGGAIRLGNTLGSDGENLPQADIVATNPPFGSAAGTNITRTFVHPTSNKQLCFMQHIIETLPPGGRAAAVVPDNVLFEGGKGTDIRRDLMDKCHLHTILRLPTGIFYAQGVKTNVLFFTKGTVANPNQDKNCTDDVWVYDLRTNMPSFGKRTPFTEQHLQPFETVYGEDPHGLSPRTEGEWSFNAEESEVADSEENKNADQHQATSRWRKFSREWIRTAKSDSLDISWLKDKDSIDADSLPEPDVLAAEAMGELVQALGELDALMRELGAGDEADAQRQLLEEAFGGVKA |
Interaction
Subunit
The type I restriction/modification system is composed of three polypeptides R, M and S; the restriction enzyme has stoichiometry R2M2S1 while the methyltransferase is M2S1.
Structure
Family & Domains
Features
Showing features for region, compositional bias.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Region | 424-443 | Disordered | ||||
Sequence: AEESEVADSEENKNADQHQA | ||||||
Compositional bias | 429-443 | Basic and acidic residues | ||||
Sequence: VADSEENKNADQHQA |
Sequence similarities
Belongs to the N(4)/N(6)-methyltransferase family.
Family and domain databases
Sequence
- Sequence statusComplete
- Length529
- Mass (Da)58,906
- Last updated1995-02-01 v2
- Checksum07895A9ADA4FA249
Features
Showing features for compositional bias.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Compositional bias | 429-443 | Basic and acidic residues | ||||
Sequence: VADSEENKNADQHQA |