Protein Family Models

Gene:

sppA

Date:

2021-09-02

The related but duplicated, double-length protein SppA (protease IV) of E. coli was shown experimentally to degrade signal peptides as are released by protein processing and secretion. This protein shows stronger homology to the C-terminal region of SppA than to the N-terminal domain or to the related putative protease SuhB. The member of this family from Bacillus subtilis was shown to have properties consistent with a role in degrading signal peptides after cleavage from precursor proteins, although it was not demonstrated conclusively.

Gene:

sppA

Date:

2021-05-12

This HMM represents the signal peptide peptidase A (SppA, protease IV) as found in E. coli, Treponema pallidum, Mycobacterium leprae, and several other species, in which it has a molecular mass around 67 kDa and a duplication such that the N-terminal half shares extensive homology with the C-terminal half. This enzyme was shown in E. coli to form homotetramers. E. coli SohB, which is most closely homologous to the C-terminal duplication of SppA, is predicted to perform a similar function of small peptide degradation, but in the periplasm. Many prokaryotes have a single SppA/SohB homolog that may perform the function of either or both.

Gene:

sppA

Date:

2023-12-19