This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Han, D C Articles by Winans, S C Search for Related Content PubMed PubMed Citation Articles by Han, D C Articles by Winans, S C

research-article

Altered-function mutations of the transcriptional regulatory gene virG of Agrobacterium tumefaciens.

Section of Microbiology, Cornell University, Ithaca, New York 14853.

ABSTRACT

Three point mutations were isolated in the Agrobacterium tumefaciens virG gene by screening for vir gene expression in the absence of added phenolic inducing compounds. All three mutations were localized in the predicted amino-terminal phosphoryl receiver domain of the protein. One mutant (N54D) bypasses the requirement for VirA and phenolic inducers both for transcriptional activation of all tested vir promoters and for plant tumorigenesis. This mutant also activates vir gene expression efficiently at neutral pH, indicating that the step in induction that is normally stimulated by acid pH occurs before or during VirG phosphorylation. The other two mutants (M13T and H15R) require VirA for activity but are sensitized to low levels of inducing stimuli.

This article has been cited by other articles:

• Gao, R., Mukhopadhyay, A., Fang, F., Lynn, D. G. (2006). Constitutive Activation of Two-Component Response Regulators: Characterization of VirG Activation in Agrobacterium tumefaciens.. J. Bacteriol. 188: 5204-5211 [Abstract] [Full Text]  
• Gao, R., Lynn, D. G. (2005). Environmental pH Sensing: Resolving the VirA/VirG Two-Component System Inputs for Agrobacterium Pathogenesis. J. Bacteriol. 187: 2182-2189 [Abstract] [Full Text]  
• Brencic, A., Winans, S. C. (2005). Detection of and Response to Signals Involved in Host-Microbe Interactions by Plant-Associated Bacteria. Microbiol. Mol. Biol. Rev. 69: 155-194 [Abstract] [Full Text]  
• Garcia-Calderon, C. B., Garcia-Quintanilla, M., Casadesus, J., Ramos-Morales, F. (2005). Virulence attenuation in Salmonella enterica rcsC mutants with constitutive activation of the Rcs system. Microbiology 151: 579-588 [Abstract] [Full Text]  
• Gelvin, S. B. (2003). Agrobacterium-Mediated Plant Transformation: the Biology behind the "Gene-Jockeying" Tool. Microbiol. Mol. Biol. Rev. 67: 16-37 [Abstract] [Full Text]  
• Lohrke, S. M., Nechaev, S., Yang, H., Severinov, K., Jin, S. J. (1999). Transcriptional Activation of Agrobacterium tumefaciens Virulence Gene Promoters in Escherichia coli Requires the A. tumefaciens rpoA Gene, Encoding the Alpha Subunit of RNA Polymerase. J. Bacteriol. 181: 4533-4539 [Abstract] [Full Text]