Linked Life Data

15660998

Source:http://linkedlifedata.com/resource/pubmed/id/15660998

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2005-1-21
pubmed:abstractText
LuxR-type transcriptional regulators play key roles in quorum-sensing systems that employ acyl-homoserine lactones (acyl-HSLs) as signal molecules. These proteins mediate quorum control by changing their interactions with RNA polymerase and DNA in response to binding their cognate acyl-HSL. The evolutionarily related LuxR-type proteins exhibit considerable diversity in primary sequence and in their response to acyl-HSLs having acyl groups of differing length and composition. Little is known about which residues determine acyl-HSL specificity, and less about the evolutionary time scales required to forge new ones. To begin to examine such issues, we have focused on the LuxR protein from Vibrio fischeri, which activates gene transcription in response to binding its cognate quorum signal, 3-oxohexanoyl-homoserine lactone (3OC6HSL). Libraries of luxR mutants were screened for variants exhibiting increased gene activation in response to octanoyl-HSL (C8HSL), with which wild-type LuxR interacts only weakly. Eight LuxR variants were identified that showed a 100-fold increase in sensitivity to C8HSL; these variants also displayed increased sensitivities to pentanoyl-HSL and tetradecanoyl-HSL, while maintaining a wild-type or greater response to 3OC6HSL. The most sensitive variants activated gene transcription as strongly with C8HSL as the wild type did with 3OC6HSL. With one exception, the amino acid residues involved were restricted to the N-terminal, 'signal-binding' domain of LuxR. These residue positions differed from critical positions previously identified via 'loss-of-function' mutagenesis. We have demonstrated that acyl-HSL-dependent quorum-sensing systems can evolve rapidly to respond to new acyl-HSLs, suggesting that there may be an evolutionary advantage to maintaining such plasticity.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0950-382X
pubmed:author
pubmed:issnType
Print
pubmed:volume
55
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
712-23
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Directed evolution of Vibrio fischeri LuxR for increased sensitivity to a broad spectrum of acyl-homoserine lactones.
pubmed:affiliation
Biochemistry and Molecular Biophysics, California Institute of Technology, Pasadena, CA 91125, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't