O82882 · STCE_ECO57

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

Zn2+ (UniProtKB | Rhea| CHEBI:29105 )

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 μMMUC7
0.27 μMSERPING1
Vmax pH TEMPERATURE[C] NOTES EVIDENCE
70.2 nM/min/ugfor MUC7 cleavage
66.8 nM/min/ugfor 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
IDPosition(s)Description
Binding site446Zn2+ (UniProtKB | ChEBI); catalytic
Active site447
Binding site450Zn2+ (UniProtKB | ChEBI); catalytic
Binding site456Zn2+ (UniProtKB | ChEBI); catalytic

GO annotations

AspectTerm
Cellular Componentextracellular region
Molecular Functionmetal ion binding
Molecular Functionmetalloendopeptidase activity
Biological Processproteolysis

Keywords

Enzyme and pathway databases

Protein family/group databases

Names & Taxonomy

Protein names

  • Recommended name
    Metalloprotease StcE
  • EC number
  • Alternative names
    • Mucinase
    • Neutral zinc metalloprotease StcE
    • Secreted protease of C1 esterase inhibitor from EHEC

Gene names

    • Name
      stcE
    • Synonyms
      tagA
    • Ordered locus names
      L7031, ECO57PM83

Encoded on

  • Plasmid pO157

Organism names

  • Taxonomic identifier
  • Strains
    • O157:H7 / EDL933 / ATCC 700927 / EHEC
    • O157:H7 / Sakai / RIMD 0509952 / EHEC
  • Taxonomic lineage
    Bacteria > Pseudomonadota > Gammaproteobacteria > Enterobacterales > Enterobacteriaceae > Escherichia

Accessions

  • Primary accession
    O82882
  • Secondary accessions
    • Q647K0
    • Q799Q8
    • Q7BSW2
    • Q9ZAL1
    • Q9ZGU1

Proteomes

Subcellular Location

Secreted
Note: Secreted via the etp type II secretion pathway.

Keywords

Phenotypes & Variants

Features

Showing features for mutagenesis.

TypeIDPosition(s)Description
Mutagenesis447Prevents 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
IDPosition(s)Description
Signal1-35
ChainPRO_000024814536-898Metalloprotease StcE

Expression

Induction

Up-regulated by the LEE (locus of enterocyte effacement)-encoded regulator ler.

Interaction

Binary interactions

TypeEntry 1Entry 2Number of experimentsIntAct
XENO O82882SERPING1 P051553EBI-15979286, EBI-1223454

Protein-protein interaction databases

Family & Domains

Features

Showing features for domain.

TypeIDPosition(s)Description
Domain296-551Peptidase M66

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Sequence processing
    The displayed sequence is further processed into a mature form.
  • Length
    898
  • Mass (Da)
    99,548
  • Last updated
    1999-11-01 v2
  • Checksum
    3C1AE23E3EAE1FAB
MNTKMNERWRTPMKLKYLSCTILAPLAIGVFSATAADNNSAIYFNTSQPINDLQGSLAAEVKFAQSQILPAHPKEGDSQPHLTSLRKSLLLVRPVKADDKTPVQVEARDDNNKILGTLTLYPPSSLPDTIYHLDGVPEGGIDFTPHNGTKKIINTVAEVNKLSDASGSSIHSHLTNNALVEIHTANGRWVRDIYLPQGPDLEGKMVRFVSSAGYSSTVFYGDRKVTLSVGNTLLFKYVNGQWFRSGELENNRITYAQHIWSAELPAHWIVPGLNLVIKQGNLSGRLNDIKIGAPGELLLHTIDIGMLTTPRDRFDFAKDKEAHREYFQTIPVSRMIVNNYAPLHLKEVMLPTGELLTDMDPGNGGWHSGTMRQRIGKELVSHGIDNANYGLNSTAGLGENSHPYVVAQLAAHNSRGNYANGIQVHGGSGGGGIVTLDSTLGNEFSHEVGHNYGLGHYVDGFKGSVHRSAENNNSTWGWDGDKKRFIPNFYPSQTNEKSCLNNQCQEPFDGHKFGFDAMAGGSPFSAANRFTMYTPNSSAIIQRFFENKAVFDSRSSTGFSKWNADTQEMEPYEHTIDRAEQITASVNELSESKMAELMAEYAVVKVHMWNGNWTRNIYIPTASADNRGSILTINHEAGYNSYLFINGDEKVVSQGYKKSFVSDGQFWKERDVVDTREARKPEQFGVPVTTLVGYYDPEGTLSSYIYPAMYGAYGFTYSDDSQNLSDNDCQLQVDTKEGQLRFRLANHRANNTVMNKFHINVPTESQPTQATLVCNNKILDTKSLTPAPEGLTYTVNGQALPAKENEGCIVSVNSGKRYCLPVGQRSGYSLPDWIVGQEVYVDSGAKAKVLLSDWDNLSYNRIGEFVGNVNPADMKKVKAWNGQYLDFSKPRSMRVVYK

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
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

Genome annotation databases

Similar Proteins

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