Open AccessClpXP controls the expression of LEE genes in enterohaemorrhagic Escherichia coli
Author(s) -
Tomoyasu Toshifumi,
Takaya Akiko,
Handa Yutaka,
Karata Kiyonobu,
Yamamoto Tomoko
Publication year - 2005
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1016/j.femsle.2005.09.020
Subject(s) - virulence , biology , pathogenicity island , rpos , secretion , promoter , escherichia coli , type three secretion system , transcription (linguistics) , mutant , genetics , gene , microbiology and biotechnology , gene expression , biochemistry , linguistics , philosophy
Enterohaemorrhagic Escherichia coli (EHEC) contains a 36‐kb pathogenicity island termed the locus of enterocyte effacement (LEE), which encodes a type III secretion system (TTSS) and virulence proteins. In this paper, we show that the O157:H7 Sakai clpPX mutant strongly impaired the secretion of virulence proteins by TTSS and repressed transcription from all the LEE promoters. The rpoS mutation in O157:H7 Sakai enhanced the transcription from all the LEE promoters and the secretion of virulence proteins, and it could partially suppress the defects of the clpPX mutation. These data indicate that the O157:H7 Sakai ClpXP protease is a positive regulator for LEE expression and that this regulation occurs by two pathways: the σ S ‐dependent and ‐independent pathways.