Domain architecture and sequence identity among the InvE-family of T3SS proteins.

<p>YopN and TyeA from human pathogen <i>Yersinia</i> sp. are two distinct polypeptides (A). In several other T3SSs, homologues to both YopN and TyeA exist as a single polypeptide (for example, InvE, MxiC, SepL, SsaL and HrpJ). Numbers in parentheses indicate the full length (in amino acids) of each protein. Other numbers indicate the bordering amino acids that demarcate YopN homology (blue shade) that is defined Pfam as a HrpJ-like domain (pfam07201), TyeA homology (orange shade) or functionally relevant regions of YopN (various coloured solid lines). The schematic illustration of YopN and TyeA homology domains within the InvE-family was derived from comprehensive multiple sequence alignments coupled to a Conserved Domain Database (CDD) [32,33]. SS, secretion signal [80]; CBD, T3S chaperone (YscB-SycN heterodimer) binding domain [92]; CCD1 and CCD2, coiled-coil domain 1 and 2 [61]; TyeA BD, TyeA binding domain [61,92]. Percent amino acid sequence identity between the InvE family of proteins was determined by BLASTP analysis for the N-terminal HrpJ-like domain (equivalent to YopN) (B) and the C-terminal TyeA-like domain (C). Representative sequences were retrieved from the NCIB genome database archived with the following GI reference numbers shown in parentheses: <i>Y</i>. <i>ps, Yersinia pseudotuberculosis</i> YopN (48634); <i>Y</i>. <i>ps</i> TyeA (48635); <i>S</i>. <i>ty, Salmonella enterica Typhimurium</i> InvE (16766203); <i>S</i>. <i>fl, Shigella flexneri</i> MxiC (12329090); <i>E</i>. <i>co, Escherichia coli</i> SepL (215267040); <i>S</i>. <i>ty</i> SsaL (16419933); <i>E</i>. <i>ch, Erwinia chrysanthemi</i> HrpJ (28628125).