TABLE 4.

Comparison of the E. ictaluri TTSS to the E. tarda and Salmonella pathogenicity island 2-encoded TTSS and putative functions

E. ictaluri geneaTotal no. of amino acids of product% Identity/similarity at the amino acid level to gene product of:Putative TTSS function
E. tardaS. enterica serovar Typhimurium
esaL34188/9228/47Regulation of translocon expression
esaK21780/8822/56Apparatus protein with glutamine-rich region
esaW (orf19)19490/9430/55Apparatus protein with leucine-rich region
esaJ24388/9441/59Outer membrane protein of the needle complex
esaI8378/9043/64Apparatus protein
esaH8890/9430/57Apparatus protein
esaG7390/9846/69Apparatus protein
esrC23096/97AraC family regulatory protein
esaE (orf13)7488/9425/45Hypothetical protein
esaD39982/8724/42Periplasmic channel
esaC49493/9546/67Oligomeric outer membrane secretin
esaB15989/9127/77Outer membrane component
eseGb30170/7926/44Effector protein
escB16388/9230/46sseF and sseG chaperone
eseE12792/9625/49Chaperone
eseD19378/8927/54Translocon protein
eseC50878/8827/48Translocon protein
escA15592/9630/53Chaperone
eseB19877/8733/52Translocon filament protein
escCc(orf2)14080/8625/58Unknown
esaQ30486/9039/57Apparatus protein that regulates translocation
esaP (orf1A)15991/9517/49Apparatus protein, integral membrane protein
esaO (orf1B)12280/8324/64Apparatus protein containing leucine zipper
esaN43890/9455/68Apparatus protein, ATP synthase
esaV68593/9652/69Apparatus membrane protein
esaM12690/9329/47Apparatus protein, secretion regulator
esaR25096/9958/76Integral apparatus membrane protein
esaS8996/9752/71Integral apparatus membrane protein
esaT26093/9643/64Integral apparatus membrane protein
esaU35289/9443/60Integral apparatus membrane protein
slt (orf26)22081/8530/65Soluble lytic murein transglycosylase
esrA93790/9332/48Regulatory sensor kinase
esrB21496/9848/66Response regulator
  • a Where named differently, comparable E. tarda genes are in parentheses. L-ALIGN and protein structure analysis of the E. ictaluri homologues of E. tarda orf2, orf1A, orf1B, orf13, orf19, and orf26 demonstrated significant similarity to the S. enterica serovar Typhimurium homologues, and the E. ictaluri homologues are named accordingly.

  • b Based on analysis of sixfold coverage of the E. ictaluri genome in this region, E. ictaluri encodes an eseG gene that has a truncated amino terminus due to the loss of an A at position 11382 of the DQ233733 sequence that introduces a stop codon. The E. ictaluri ureG gene starts at bp 120 of the E. tarda ureG gene.

  • c Formerly eseA (see reference 88).