P18011 · SCTE_SHIFL

  • Protein
    Type 3 secretion system translocon protein SctE
  • Gene
    sctE
  • Status
    UniProtKB reviewed (Swiss-Prot)
  • Amino acids
  • Protein existence
    Evidence at protein level
  • Annotation score
    5/5

Function

function

Component of the type III secretion system (T3SS), also called injectisome, which is used to inject bacterial effector proteins into eukaryotic host cells (PubMed:10545510, PubMed:17367391).
IpaB/SctE and IpaC/SctB are inserted into the host membrane where they form a pore and allow the translocation of effector proteins into the cytosol of target cells (PubMed:10545510, PubMed:17367391, PubMed:34809452).
Interaction with IpaD/SctA at needle tips leads to the formation of the MxiH/SctF-IpaD/SctA-IpaB/SctE ternary complex, which is essential for host cell sensing (PubMed:17367391, PubMed:19433542).
Interaction of IpaB/SctE with host membrane lipids promotes recruitment of IpaC/SctB at the needle tip concomitant with translocon insertion into the host membrane and type III secretion induction (PubMed:19433542).
Required for efficient dissemination (PubMed:11207551).
Necessary for lysis of the two cellular membranes that surround bacteria in protrusions during cell-to-cell spread (PubMed:11207551).
Is sufficient to induce macrophage apoptosis through activation of the interleukin-1 beta converting enzyme (ICE) in infected macrophages (PubMed:8670890, PubMed:9009343).
In epithelial cells, causes cell-cycle arrest by targeting host MAD2L2, an anaphase-promoting complex/cyclosome (APC) inhibitor (PubMed:17719540).

Activity regulation

Interaction with the membrane is affected by the pH (PubMed:10971588).
IpaB/SctE is more efficient in destabilizing the membrane at pH 5.0 than at neutral pH (PubMed:10971588).

GO annotations

AspectTerm
Cellular Componentextracellular region
Cellular Componenthost cell
Cellular Componenthost cell membrane
Cellular Componenthost cell nucleus
Cellular Componentmembrane

Keywords

Names & Taxonomy

Protein names

  • Recommended name
    Type 3 secretion system translocon protein SctE
  • Short names
    T3SS translocon protein SctE
  • Alternative names
    • 62 kDa antigen
    • Invasin IpaB

Gene names

    • Name
      sctE
    • Synonyms
      ipaB
    • Ordered locus names
      CP0128

Encoded on

  • Plasmid pWR100
  • Plasmid pWR501
  • Plasmid pMYSH6000
  • Plasmid pCP301

Organism names

  • Taxonomic identifier
  • Strains
    • M90T / Serotype 5a
    • YSH6000 / Serotype 2a
    • 301 / Serotype 2a
  • Taxonomic lineage
    Bacteria > Pseudomonadota > Gammaproteobacteria > Enterobacterales > Enterobacteriaceae > Shigella

Accessions

  • Primary accession
    P18011

Proteomes

Subcellular Location

Secreted
Host membrane
; Multi-pass membrane protein
Host cell
Host nucleus
Note: Secreted via the type III secretion system (T3SS) (PubMed:10545510).
Localizes at the surface of needle tips via IpaD/SctA (PubMed:17367391).
IpaB/SctE and IpaC/SctB form a multimeric integral membrane complex in eukaryotic cell membranes (PubMed:10545510, PubMed:17367391).
Also secreted into the cytoplasm of the infected macrophage after the escape of bacteria from phagosome, where it colocalizes with ICE (PubMed:8670890, PubMed:9009343).
May localize to host cell nucleus during G2/M phase of the host cell cycle (PubMed:17719540).

Features

Showing features for transmembrane.

TypeIDPosition(s)Description
Transmembrane313-333Helical
Transmembrane399-419Helical

Keywords

Phenotypes & Variants

Disruption phenotype

Deletion mutant shows fast constitutive secretion and displays increased adhesion to HeLa cells (PubMed:20086081).
Mutant is non-hemolytic in the presence of sheep red blood cell (RBC) (PubMed:10545510, PubMed:20086081).
Mutant displays normal secretons (PubMed:10545510).

Features

Showing features for natural variant, mutagenesis.

TypeIDPosition(s)Description
Natural variant18in plasmid pMYSH6000 and plasmid pCP301
Mutagenesis61Loss of interaction with human MAD2L2.
Mutagenesis572-580Shows fast constitutive secretion. Partially invasive and hyperadhesive. Can still form pores by inserting itself and IpaC/SctB into membranes, but is completely unable to lyse red blood cells. Does not affect the ability of Shigella to lyse the epithelial cell invasion vacuole. Affects IpaB/SctE ability to bind needle tips and leads to increased IpaC/SctB recruitment to purified needles.
Mutagenesis578-580Shows fast constitutive secretion. Partially invasive and hyperadhesive. Can still form pores by inserting itself and IpaC/SctB into membranes, but is completely unable to lyse red blood cells. Does not affect the ability of Shigella to lyse the epithelial cell invasion vacuole. Affects IpaB/SctE ability to bind needle tips and leads to increased IpaC/SctB recruitment to purified needles.

Variants

We now provide the "Disease & Variants" viewer in its own tab.

The viewer provides 1 variant from UniProt as well as other sources including ClinVar and dbSNP.

Go to variant viewer

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00002198531-580Type 3 secretion system translocon protein SctE

Proteomic databases

Expression

Induction

Synthesis of this immunogen is repressed at 30 degrees Celsius and restored at 37 degrees Celsius.

Interaction

Subunit

The core secretion machinery of the T3SS is composed of approximately 20 different proteins, including cytoplasmic components, a base, an export apparatus and a needle (PubMed:30107569).
This subunit is involved in the formation of a pore, called the translocon, in host membrane (PubMed:10545510, PubMed:17367391, PubMed:34809452).
Interacts with IpaC/SctB (PubMed:10545510, PubMed:17367391, PubMed:7954817).
Interacts with the needle tip protein IpaD/SctA (PubMed:17367391, PubMed:24236510).
Interacts with the molecular chaperone IpgC, which prevents premature association with IpaC/SctB within the cytoplasm of Shigella cells and protects IpaB/SctE from proteolysis (PubMed:11207551, PubMed:19478065, PubMed:20937829, PubMed:7954817).
Interacts with the host protein ICE in the cytoplasm of infected macrophages (PubMed:8670890).
Interacts with human MAD2L2 in the G2/M phase of the cell cycle (PubMed:17719540, PubMed:31484720).

Binary interactions

Protein-protein interaction databases

Family & Domains

Features

Showing features for region, coiled coil.

TypeIDPosition(s)Description
Region15-45IpgC chaperone binding domain 1
Region51-72IpgC chaperone binding domain 2
Region61-70Mediates interaction with human MAD2L2
Coiled coil104-224

Domain

The immediate N-terminus is needed for recognition by the secretion apparatus and chaperone binding (PubMed:29672980).
The N-terminal region is necessary for interaction with IpaD/SctA and the sequential maturation of the T3SS needle tip (PubMed:24236510).
The C-terminal half is key to the activities needed for formation of an active translocon and possibly for translocation itself (PubMed:29672980).
The extreme C-terminus is required for efficient needle tip binding, and its absence also affects regulation of secretion and adhesion to and possibly invasion of host cells (PubMed:20086081).
Portion of the translocon pore channel adopts a funnel-like conformation, wherein it narrows toward the cytosolic side of the plasma membrane (PubMed:34809452).

Sequence similarities

Belongs to the SctE/SipB/YopB family.

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    580
  • Mass (Da)
    62,201
  • Last updated
    1994-02-01 v2
  • Checksum
    56325105E4BC0F70
MHNVSTTTTGFPLAKILTSTELGDNTIQAANDAANKLFSLTIADLTANQNINTTNAHSTSNILIPELKAPKSLNASSQLTLLIGNLIQILGEKSLTALTNKITAWKSQQQARQQKNLEFSDKINTLLSETEGLTRDYEKQINKLKNADSKIKDLENKINQIQTRLSELDPESPEKKKLSREEIQLTIKKDAAVKDRTLIEQKTLSIHSKLTDKSMQLEKEIDSFSAFSNTASAEQLSTQQKSLTGLASVTQLMATFIQLVGKNNEESLKNDLALFQSLQESRKTEMERKSDEYAAEVRKAEELNRVMGCVGKILGALLTIVSVVAAAFSGGASLALAAVGLALMVTDAIVQAATGNSFMEQALNPIMKAVIEPLIKLLSDAFTKMLEGLGVDSKKAKMIGSILGAIAGALVLVAAVVLVATVGKQAAAKLAENIGKIIGKTLTDLIPKFLKNFSSQLDDLITNAVARLNKFLGAAGDEVISKQIISTHLNQAVLLGESVNSATQAGGSVASAVFQNSASTNLADLTLSKYQVEQLSKYISEAIEKFGQLQEVIADLLASMSNSQANRTDVAKAILQQTTA

Features

Showing features for sequence conflict.

TypeIDPosition(s)Description
Sequence conflict167in Ref. 2; AAA26522

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
J04117
EMBL· GenBank· DDBJ
AAA26522.1
EMBL· GenBank· DDBJ
Genomic DNA
M34849
EMBL· GenBank· DDBJ
AAA98424.1
EMBL· GenBank· DDBJ
Genomic DNA
AL391753
EMBL· GenBank· DDBJ
CAC05803.1
EMBL· GenBank· DDBJ
Genomic DNA
AF348706
EMBL· GenBank· DDBJ
AAK18446.1
EMBL· GenBank· DDBJ
Genomic DNA
X15319
EMBL· GenBank· DDBJ
CAA33381.1
EMBL· GenBank· DDBJ
Genomic DNA
AF386526
EMBL· GenBank· DDBJ
AAL72352.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

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