Open AccessPurification and characterization of LasR as a DNA‐binding protein
Author(s) -
You Zhiying,
Fukushima Jun,
Ishiwata Tetsuyoshi,
Chang Baotong,
Kurata Minoru,
Kawamoto Susumu,
Williams Paul,
Okuda Kenji
Publication year - 1996
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1996.tb08447.x
Subject(s) - activator (genetics) , fusion protein , autoinducer , biology , gene , transcription (linguistics) , binding site , microbiology and biotechnology , gene product , dna binding protein , dna , biochemistry , transcription factor , chemistry , gene expression , recombinant dna , quorum sensing , linguistics , philosophy , virulence
In Pseudomonas aeruginosa , the activator protein LasR and a cognate autoinducer (AI) are required for expression of the elastase gene ( lasB ). In the present study, we investigated the binding properties of the P. aeruginosa lasR gene product. The LasR protein was overexpressed and purified as a glutathione S ‐transferase (GST) fusion protein. Using gel retardation and UV cross‐linking analysis, we demonstrated that the GST‐LasR could bind to a separate site in the lasB upstream operator regions 1 and 3 in the presence of the autoinducer. Regions 1 and 3 are located at 105 and 42 base pairs upstream, respectively, from the lasB transcriptional start site. Our present results clearly demonstrate that LasR is a specific DNA‐binding protein that regulates the transcription of the lasB gene in the presence of an autoinducer.