title: Gene l0017 encodes a second chaperone for EspA of enterohaemorrhagic Escherichia coli O157 : H7.
abstract: Escherichia coli O157:H7 tightly associates with host cells through the formation of a pedestal structure in which cell cytoskeleton rearrangement has been observed. These pathogenic properties have been attributed to an island, known as the locus of enterocyte effacement (LEE), located on the bacterial chromosome. Gene l0017 is one of the LEE genes that has been less well characterized. To understand further the function of the gene, an l0017-deleted mutant was created. The mutant lost type III protein secretion (TTS) capacity. In terms of intracellular components, there was a substantial decrease in the level of EspA, but no apparent effect on Tir and EspB was observed. Fractionation of the bacterial proteins indicated that L0017 was part of the inner-membrane fraction. This association with the membrane is consistent with the hypothesis that L0017 may act as one of the TTS components. In addition, L0017 was found to affect regulation of EspA at a post-transcriptional level. The presence of L0017 readily stabilized EspA and the interaction between L0017 and EspA was demonstrated by their co-purification as well as by a bacterial two-hybrid system. Therefore, L0017 is a chaperone, the second chaperone identified in this system after CesAB, and escorts EspA, a protein with a great tendency to polymerize.
authors: Institute of Microbiology and Immunology, National Yang-Ming University, Beitou 112, Taipei, Taiwan.
authors: Marcia Shu-Wei
authors: MS
authors: Su
authors: Institute of Microbiology and Immunology, National Yang-Ming University, Beitou 112, Taipei, Taiwan.
authors: Hsi-Chun
authors: HC
authors: Kao
authors: Institute of Microbiology and Immunology, National Yang-Ming University, Beitou 112, Taipei, Taiwan.
authors: Ching-Nan
authors: CN
authors: Lin
authors: Institute of Microbiology and Immunology, National Yang-Ming University, Beitou 112, Taipei, Taiwan.
authors: Wan-Jr
authors: WJ
authors: Syu
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000032:analysis; D002458:Cell Fractionation; D002462:Cell Membrane / Q000737:chemistry; D019453:Escherichia coli O157 / Q000737:chemistry / Q000502:physiology*; D029968:Escherichia coli Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D005798:Genes, Bacterial; D044404:Genomic Islands; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism*; D025941:Protein Interaction Mapping; D021381:Protein Transport / Q000235:genetics; D011956:Receptors, Cell Surface / Q000032:analysis; D020798:Two-Hybrid System Techniques
chemical_list: D001425:Bacterial Outer Membrane Proteins; C087863:EaeB protein, E coli; D029968:Escherichia coli Proteins; C102051:EspA protein, E coli; D008565:Membrane Proteins; D018832:Molecular Chaperones; D011956:Receptors, Cell Surface; C109287:Tir protein, E coli