Determination of the InvE Binding Site Required for Expression of IpaB of the Shigella sonnei Virulence Plasmid: Involvement of a ParB BoxA-Like Sequence

Affordable Access

Determination of the InvE Binding Site Required for Expression of IpaB of the Shigella sonnei Virulence Plasmid: Involvement of a ParB BoxA-Like Sequence

Publisher
American Society for Microbiology
Publication Date
Sep 01, 2003
Source
PMC
Keywords
Disciplines
  • Biology
  • Design
License
Unknown

Abstract

The InvE protein positively regulates the expression of virulence genes ipaBCD in Shigella sonnei. The InvE has significant homology with ParB of plasmid P1, which is known as a plasmid partitioning factor with DNA binding ability. Although the DNA binding activity of InvE has been predicted, it is not known whether the DNA binding activity is necessary for type III secretion system-associated gene expression. In this study, we determined the transcription start site of the icsB-ipaBCD operon (ipa operon) and constructed a series of deletions of the icsB promoter region in the Escherichia coli K-12 background. The deletion study revealed that an 86-bp region upstream of the icsB transcription start site was essential for expression of the ipa operon, where the ParB binding motif (ParB BoxA-like sequence) was observed. Purified glutathione S-transferase-InvE fusion protein bound directly to the −93 to −54 region (designating the icsB transcription start site as nucleotide +1) containing the ParB BoxA-like sequence. These results indicated that InvE bound directly to the promoter region.

Report this publication

Statistics

Seen <100 times