title: A second operator is involved in Pseudomonas aeruginosa elastase (lasB) activation.
abstract: Pseudomonas aeruginosa LasB elastase gene (lasB) transcription is controlled by the two-component quorum-sensing system of LasR, and the autoinducer, 3OC(12)-HSL (N-3-[oxododecanoyl]homoserine lactone). LasR and 3OC(12)-HSL-mediated lasB activation requires a functional operator sequence (OP1) in the lasB promoter region. Optimal activation of lasB, however, requires a second sequence of 70% identity to OP1, named OP2, located 43 bp upstream of OP1. In this study, we used sequence substitutions and insertion mutations in lasBp-lacZ fusion plasmids to explore the role of OP2 in lasB activation. Our results demonstrate that (i) OP1 and OP2 synergistically mediate lasB activation; (ii) OP2, like OP1, responds to LasR and 3OC(12)-HSL; and (iii) the putative autoinducer-binding domain of LasR is not required for synergistic activation from OP1 and OP2.
authors.affiliation: Department of Veterinary and Microbiological Sciences, North Dakota State University, Fargo, North Dakota 58105, USA.
authors.forename: R M
authors.initials: RM
authors.lastname: Anderson
authors.forename: C A
authors.initials: CA
authors.lastname: Zimprich
authors.forename: L
authors.initials: L
authors.lastname: Rust
mesh_terms: D001426:Bacterial Proteins; D001483:Base Sequence; D004789:Enzyme Activation; D004790:Enzyme Induction; D015964:Gene Expression Regulation, Bacterial; D008666:Metalloendopeptidases / Q000096:biosynthesis*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009875:Operator Regions, Genetic; D011550:Pseudomonas aeruginosa / Q000201:enzymology / Q000235:genetics*; D012329:RNA, Bacterial / Q000096:biosynthesis; D012333:RNA, Messenger / Q000096:biosynthesis
chemical_list: D001426:Bacterial Proteins; D012329:RNA, Bacterial; D012333:RNA, Messenger; D008666:Metalloendopeptidases; C043859:pseudolysin, Pseudomonas aeruginosa