Role of hha and ler in transcriptional regulation of the esp operon of enterohemorrhagic Escherichia coli O157:H7.

ABSTRACT: The locus of enterocyte effacement (LEE), which includes five major operons (LEE1 through LEE4 and tir), enables enterohemorrhagic Escherichia coli (EHEC) O157:H7 to produce attaching and effacing lesions on host cells. Expression of LEE2, LEE3, and tir is positively regulated by ler, a gene located in LEE1. Transcriptional regulation of the esp operon (LEE4), however, is not well defined. Transposon mutagenesis was used to identify transcriptional regulators of the esp operon by screening for mutants with increased beta-galactosidase activity in an EHEC O157:H7 strain harboring an esp::lac transcriptional fusion. All mutants with significant increases in beta-galactosidase activity had transposon insertions in hha (hha::Tn). Specific complementation of the hha::Tn mutation with a plasmid-

SUBMITTER: Sharma VK 

PROVIDER: S-EPMC523200 | biostudies-literature | 2004 Nov

REPOSITORIES: biostudies-literature