We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Mutants ofAgrobacterium tumefaciens virGGene That Activate Transcription ofvirPromoter inEscherichia coli.
- Authors
Yong-Chul Jung; Yunrong Gu; Donghai Wu; Shouguang Jin
- Abstract
ThevirAandvirGtwo-component regulatory system is essential for transcriptional activation of virulence (vir) genes inAgrobacterium tumefaciensin the presence of inducer molecules. The VirA/VirG mediatedvirgene transcription depends on a specific interaction between the C-terminal domain of the a subunit (RpoA) ofA. tumefaciensRNA polymerase (RNAP) and N-terminal domain of the VirG. However, such interaction does not occur between RNAP ofE. coliand the VirG, thusvirgene activation inE. colirequires the presence ofrpoAgene fromA. tumefaciens. In this report, we describe VirG mutants that are capable of activating the expression ofvirgenes inE. coliin the absence ofA. tumefaciensRpoA. The selected 45 VirG mutants exhibited a common amino acid substitution at position 56 and additional one or more substitutions at different positions; thus the amino acid at position 56 is likely to play a key role in the interaction with the RpoA ofE. coli. Furthermore, twovirGmutants, with amino acid substitutions of G56V/V7I/I106N and G56V/I77V, respectively, are capable of activatingvirgenes inE. coliin response to inducer acetosyringone in avirA-dependent manner, demonstrating that the interaction site between VirG and RpoA is separable from that of VirG and VirA. Therefore, it is possible to establish inducer-mediatedvirgene expression in heterologous hosts usingvirGmutants that are capable of interacting with the RpoA of the respective bacterial hosts while retaining the ability to interact with the sensor VirA.
- Publication
Current Microbiology, 2004, Vol 49, Issue 5, p334
- ISSN
0343-8651
- Publication type
Academic Journal
- DOI
10.1007/s00284-004-4359-7