O82882 · STCE_ECO57
- ProteinMetalloprotease StcE
- GenestcE
- StatusUniProtKB reviewed (Swiss-Prot)
- Organism
- Amino acids898 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Virulence factor that contributes to intimate adherence of enterohemorrhagic E.coli (EHEC) O157:H7 to host cells. Is able to cleave the secreted human mucin 7 (MUC7) and the glycoprotein 340 (DMBT1/GP340). Also cleaves human C1 inhibitor (SERPING1), a regulator of multiple inflammatory pathways, and binds and localizes it to bacterial and host cell surfaces, protecting them from complement-mediated lysis. Therefore, the current model proposes two roles for StcE during infection: it acts first as a mucinase, allowing passage of EHEC through the oral cavity by cleaving the salivary glycoproteins that are responsible for bacterial aggregation. Similarly, in the colon, StcE cleaves the glycoproteins that protect the intestinal epithelial surface, allowing EHEC to come into close contact with host cell membranes. Secondly, it acts as an anti-inflammatory agent by localizing SERPING1 to cell membranes.
Miscellaneous
Is resistant to proteolytic degradation by trypsin, chymotrypsin, human and bacterial elastase, but not by the fungal protease proteinase K.
Cleavage of SERPING1 occurs within its heavily glycosylated N-terminal region and is different to that of elastase.
Cofactor
Note: Binds 1 zinc ion per subunit. Does not contain structural calcium, which is often associated with other metalloproteases.
Activity regulation
Inhibited by divalent cation chelators such as BPS and EDTA.
Kinetics
KM | SUBSTRATE | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|---|
0.13 μM | MUC7 | |||||
0.27 μM | SERPING1 |
Vmax | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|
70.2 nM/min/ug | for MUC7 cleavage | ||||
66.8 nM/min/ug | for SERPING1 cleavage |
Proteolytic activity is 2.5-fold more efficient with the secreted mucin MUC7 than with SERPING1.
pH Dependence
Optimum pH is 6.5-7.0. Active from pH 6.1 to 9.0.
Temperature Dependence
Optimum temperature is 37-42 degrees Celsius. Active from 4 to 55 degrees Celsius. Inactive above 60 degrees Celsius.
Features
Showing features for binding site, active site.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Binding site | 446 | Zn2+ (UniProtKB | ChEBI); catalytic | |||
Active site | 447 | ||||
Binding site | 450 | Zn2+ (UniProtKB | ChEBI); catalytic | |||
Binding site | 456 | Zn2+ (UniProtKB | ChEBI); catalytic | |||
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | extracellular region | |
Molecular Function | metal ion binding | |
Molecular Function | metalloendopeptidase activity | |
Biological Process | proteolysis |
Keywords
- Molecular function
- Biological process
- Ligand
Enzyme and pathway databases
Protein family/group databases
Names & Taxonomy
Protein names
- Recommended nameMetalloprotease StcE
- EC number
- Alternative names
Gene names
Encoded on
- Plasmid pO157
Organism names
- Organism
- Strains
- Taxonomic lineageBacteria > Pseudomonadota > Gammaproteobacteria > Enterobacterales > Enterobacteriaceae > Escherichia
Accessions
- Primary accessionO82882
- Secondary accessions
Proteomes
Subcellular Location
UniProt Annotation
GO Annotation
Note: Secreted via the etp type II secretion pathway.
Keywords
- Cellular component
Phenotypes & Variants
Features
Showing features for mutagenesis.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Mutagenesis | 447 | Prevents both cleavage and binding to SERPING1. Unable to aggregate T-cells. Still able to bind zinc. | |||
PTM/Processing
Features
Showing features for signal, chain.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Signal | 1-35 | ||||
Chain | PRO_0000248145 | 36-898 | Metalloprotease StcE | ||
Expression
Induction
Up-regulated by the LEE (locus of enterocyte effacement)-encoded regulator ler.
Interaction
Binary interactions
Type | Entry 1 | Entry 2 | Number of experiments | IntAct | |
---|---|---|---|---|---|
XENO | O82882 | SERPING1 P05155 | 3 | EBI-15979286, EBI-1223454 |
Protein-protein interaction databases
Structure
Sequence
- Sequence statusComplete
- Sequence processingThe displayed sequence is further processed into a mature form.
- Length898
- Mass (Da)99,548
- Last updated1999-11-01 v2
- Checksum3C1AE23E3EAE1FAB
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
Y11831 EMBL· GenBank· DDBJ | CAA72517.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
Y11275 EMBL· GenBank· DDBJ | CAA72142.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
AF074613 EMBL· GenBank· DDBJ | AAC70099.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
AB011549 EMBL· GenBank· DDBJ | BAA31757.3 EMBL· GenBank· DDBJ | Genomic DNA | ||
AY714880 EMBL· GenBank· DDBJ | AAU25886.1 EMBL· GenBank· DDBJ | Genomic DNA |