JBC

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
QUICK SEARCH:   [advanced]


     

A more recent version of this article appeared on September 24, 2004
This Article
Right arrow Full Text (Accepted Manuscript)
Right arrow All Versions of this Article:
279/39/40844    most recent
M405299200v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Qin, Y.
Right arrow Articles by Farrand, S. K.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Qin, Y.
Right arrow Articles by Farrand, S. K.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?

Papers In Press, published online ahead of print July 4, 2004
J. Biol. Chem, 10.1074/jbc.M405299200
Submitted on May 12, 2004
Revised on June 24, 2004
Accepted on July 4, 2004

Domains formed within the N-terminal region of the quorum-sensing activator TraR are required for transcriptional activation and direct interaction with RpoA from agrobacterium

Yinping Qin, Zhao-Qing Luo, and Stephen K. Farrand

Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801

Corresponding Author: stephenf{at}uiuc.edu

TraR, a quorum-sensing activator, induces transcription from its binding site, the tra-box, located upstream of Ti plasmid target promoters. TraR activated expression of a lacZ reporter in Escherichia coli only when RpoAAt from Agrobacterium tumefaciens was co-expressed. As assessed by gel retardation assays RpoAAt, but not RpoAEc formed a ternary complex with TraR and a tra-box probe in vitro. TraR formed similar ternary complexes with alpha CTDAt but not with alpha NTDAt, the C- and N-terminal segments of RpoAAt. As measured by surface plasmon resonance refractometry TraR interacted directly with RpoAAt with an affinity about five times greater than that observed for its interaction with RpoA Ec. The activator interacted with alpha CTDAt with kinetics and affinities similar to those of the full-sized - alpha subunit. Positive-control (PC) mutations at Asp-10 and Gly-123 of TraR did not affect DNA binding but greatly decreased the TraR-RpoAAt interaction. These two residues combine to form two patches on the activator one of which may be involved in interaction with RpoA. When co-expressed, mutants of TraR with substitutions at Asp-10 complemented mutants with substitutions at Gly-123 for gene activation in an allele-specific manner. Co-expression studies with TraR and its PC mutants, and also with complementing PC alleles of TraR, coupled with three-dimensional structure are consistent with a hypothesis that both Asp-10/Gly-123 patches are required for activator function.


Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati    What's this?


This article has been cited by other articles:


Home page
 J. Biol. Chem.Home page
S. Castang, S. Reverchon, P. Gouet, and W. Nasser
Direct Evidence for the Modulation of the Activity of the Erwinia chrysanthemi Quorum-sensing Regulator ExpR by Acylhomoserine Lactone Pheromone
J. Biol. Chem., October 6, 2006; 281(40): 29972 - 29987.
[Abstract] [Full Text] [PDF]

Home page
 J. Bacteriol.Home page
H. Zheng, Z. Zhong, X. Lai, W.-X. Chen, S. Li, and J. Zhu
A LuxR/LuxI-Type Quorum-Sensing System in a Plant Bacterium, Mesorhizobium tianshanense, Controls Symbiotic Nodulation.
J. Bacteriol., March 1, 2006; 188(5): 1943 - 1949.
[Abstract] [Full Text] [PDF]

Home page
 J. Bacteriol.Home page
S. R. Khan, D. V. Mavrodi, G. J. Jog, H. Suga, L. S. Thomashow, and S. K. Farrand
Activation of the phz Operon of Pseudomonas fluorescens 2-79 Requires the LuxR Homolog PhzR, N-(3-OH-Hexanoyl)-L-Homoserine Lactone Produced by the LuxI Homolog PhzI, and a cis-Acting phz Box
J. Bacteriol., September 15, 2005; 187(18): 6517 - 6527.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
 All ASBMB Journals   Molecular and Cellular Proteomics 
 Journal of Lipid Research   ASBMB Today 
Copyright © 2004 by the American Society for Biochemistry and Molecular Biology.