title: Environmental pH sensing: resolving the VirA/VirG two-component system inputs for Agrobacterium pathogenesis.
abstract: Agrobacterium tumefaciens stands as one of biotechnology's greatest successes, with all plant genetic engineering building on the strategies of this pathogen. By integrating responses to external pHs, phenols, and monosaccharides, this organism mobilizes oncogenic elements to efficiently transform most dicotyledonous plants. We now show that the complex signaling network used to regulate lateral gene transfer can be resolved as individual signaling modules. While pH and sugar perception are coupled through a common pathway, requiring both low pH and sugar for maximal virulence gene expression, various VirA and ChvE alleles can decouple pH and monosaccharide perception. This VirA and ChvE system may represent a common mechanism that underpins external pH perception in prokaryotes, and the use of these simple genetic elements may now be extended to research on specific responses to changes in environmental pH.
authors.affiliation: Center for Fundamental and Applied Molecular Evolution, Department of Chemistry, Emory University, Atlanta, GA 30322, USA.
authors.forename: Rong
authors.initials: R
authors.lastname: Gao
authors.forename: David G
authors.initials: DG
authors.lastname: Lynn
mesh_terms: D016960:Agrobacterium tumefaciens / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D050260:Carbohydrate Metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004777:Environment; D006863:Hydrogen-Ion Concentration; D026901:Membrane Transport Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016296:Mutagenesis; D033902:Periplasmic Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017434:Protein Structure, Tertiary; D015398:Signal Transduction / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D026901:Membrane Transport Proteins; D033902:Periplasmic Binding Proteins; D014157:Transcription Factors; D037521:Virulence Factors; C058483:virG protein, Shigella flexneri
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