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  Domain Name: S26_SPase_I
The S26 Type I signal peptidase (SPase; LepB; leader peptidase B; leader peptidase I; EC family members are essential membrane-bound serine proteases that function to cleave the amino-terminal signal peptide extension from proteins that are translocated across biological membranes. The bacterial signal peptidase I, which is the most intensively studied, has two N-terminal transmembrane segments inserted in the plasma membrane and a hydrophilic, C-terminal catalytic region that is located in the periplasmic space. Although the bacterial signal peptidase I is monomeric, signal peptidases of eukaryotic cells commonly function as oligomeric complexes containing two divergent copies of the catalytic monomer. These are the IMP1 and IMP2 signal peptidases of the mitochondrial inner membrane that remove leader peptides from nuclear- and mitochondrial-encoded proteins. Also, two components of the endoplasmic reticulum signal peptidase in mammals (18-kDa and 21-kDa) belong to this family and they process many proteins that enter the ER for retention or for export to the Golgi apparatus, secretory vesicles, plasma membranes or vacuole. An atypical member of the S26 SPase type I family is the TraF peptidase which has the remarkable activity of producing a cyclic protein of the Pseudomonas pilin system. The type I signal peptidases are unique serine proteases that utilize a serine/lysine catalytic dyad mechanism in place of the classical serine/histidine/aspartic acid catalytic triad mechanism.
No pairwise interactions are available for this conserved domain.

Total Mutations Found: 0
Total Disease Mutations Found: 0
This domain occurred 4 times on human genes (4 proteins).

 If you've navigated here from a protein, hovering over a position on the weblogo will display the corresponding protein position for that domain position.

 The histograms below the weblogo indicate mutations found on the domain. Red is for disease (OMIM) and blue is for SNPs.

 Functional Features are displayed as orange boxes under the histograms. You can choose which features are displayed in the box below.

Range on the Protein:  

   Protein ID            Protein Position

Domain Position:  

Feature Name:Total Found:
Catalytic site

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Please Cite: Peterson, T.A., Adadey, A., Santana-Cruz ,I., Sun, Y., Winder A, Kann, M.G., (2010) DMDM: Domain Mapping of Disease Mutations. Bioinformatics 26 (19), 2458-2459.

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