Phase variation controls expression of Salmonella lipopolysaccharide modification genes by a DNA methylation‐dependent mechanism
Open Access
- 5 July 2010
- journal article
- Published by Wiley in Molecular Microbiology
- Vol. 77 (2), 337-353
- https://doi.org/10.1111/j.1365-2958.2010.07203.x
Abstract
The O-antigen of Salmonella lipopolysaccharide is a major antigenic determinant and its chemical composition forms the basis for Salmonella serotyping. Modifications of the O-antigen that can affect the serotype include those carried out by the products of glycosyltransferase operons (gtr), which are present on specific Salmonella and phage genomes. Here we show that expression of the gtr genes encoded by phage P22 that confers the O1 serotype is under the control of phase variation. This phase variation occurs by a novel epigenetic mechanism requiring OxyR in conjunction with the DNA methyltransferase Dam. OxyR is an activator or a repressor of the system depending on which of its two binding sites in the gtr regulatory region is occupied. Binding is decreased by methylation at Dam target sequences in either site, and this confers heritability of the expression state to the system. Most Salmonella gtr operons share the key regulatory elements that are identified here as essential for this epigenetic phase variation.Keywords
This publication has 70 references indexed in Scilit:
- Establishing and Maintaining Sequestration of Dam Target Sites for Phase Variation ofagn43inEscherichia coliJournal of Bacteriology, 2010
- Regulation ofSalmonella entericaPathogenicity Island 1 by DNA Adenine MethylationGenetics, 2010
- Roles of DNA adenine methylation in host–pathogen interactions: mismatch repair, transcriptional regulation, and moreFEMS Microbiology Reviews, 2009
- Genomic analysis of bacteriophage ε34 of Salmonella entericaserovar Anatum (15+)BMC Microbiology, 2008
- Neisseria meningitidis Escape from the Bactericidal Activity of a Monoclonal Antibody Is Mediated by Phase Variation of lgtG and Enhanced by a Mutator PhenotypeInfection and Immunity, 2008
- Modulation of Escherichia coli DNA Methyltransferase Activity by Biologically Derived GATC-flanking SequencesPublished by Elsevier BV ,2008
- Clustal W and Clustal X version 2.0Bioinformatics, 2007
- Epigenetic Gene Regulation in the Bacterial WorldMicrobiology and Molecular Biology Reviews, 2006
- GATC Flanking Sequences Regulate Dam Activity: Evidence for how Dam Specificity may Influence pap ExpressionJournal of Molecular Biology, 2006
- Phase Variation of Ag43 Is Independent of the Oxidation State of OxyRJournal of Bacteriology, 2003