A Second Operator Is Involved in Pseudomonas aeruginosa Elastase (lasB) Activation
AUTOR(ES)
Anderson, Ronda M.
FONTE
American Society for Microbiology
RESUMO
Pseudomonas aeruginosa LasB elastase gene (lasB) transcription is controlled by the two-component quorum-sensing system of LasR, and the autoinducer, 3OC12-HSL (N-3-[oxododecanoyl]homoserine lactone). LasR and 3OC12-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 3OC12-HSL; and (iii) the putative autoinducer-binding domain of LasR is not required for synergistic activation from OP1 and OP2.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=103758Documentos Relacionados
- Analysis of the Pseudomonas aeruginosa elastase (lasB) regulatory region.
- lasA and lasB genes of Pseudomonas aeruginosa: analysis of transcription and gene product activity.
- Pseudomonas aeruginosa lasB1 mutants produce an elastase, substituted at active-site His-223, that is defective in activity, processing, and secretion.
- Substitution of active-site His-223 in Pseudomonas aeruginosa elastase and expression of the mutated lasB alleles in Escherichia coli show evidence for autoproteolytic processing of proelastase.
- Positive correlation of algD transcription to lasB and lasA transcription by populations of Pseudomonas aeruginosa in the lungs of patients with cystic fibrosis.
