1. Structural features of seven streptococcal cell surface proteins that function in adherence and colonization.
Structural features of seven streptococcal cell surface proteins that function in adherence and colonization. Emm6, S. pyogenes; SpaP, S. mutans; Spg, S. dysgalactiae; SfbI, S. pyogenes; Hsa, S. gordonii; SclA, S. pyogenes; ScpB, S. agalactiae. Precursor polypeptides are drawn N terminal (left) to C terminal (right), and all of the proteins are thought to be held at the cell surface through covalent cell wall anchorage (CWA) via a specialized C-terminal motif (see text). Leader (signal) peptides (SP) are cleaved at conventional sites by signal peptidase I. Specific structural features and amino acid residue repeat block regions are indicated (see descriptions in the text). Like-shaded regions across the different proteins indicate only similarities in amino acid composition or predicted secondary structure, e.g., α-helical coiled coil, and not sequence homologies. Conversely, amino acid residue repeat blocks within a polypeptide, e.g., SpaP, are highly conserved. Some of the substrates bound by the polypeptides, and the approximate locations of the binding sites, are indicated below each structure. fH, factor H; gp340, cysteine-rich scavenger protein (salivary agglutinin).
Angela H. Nobbs et al. Microbiol. Mol. Biol. Rev. 2009; doi: /MMBR