A novel strategy for the isolation of luxl homologues: evidence for the widespread distribution of a LuxR:Luxl superfamily in enteric bacteria
Article first published online: 27 OCT 2006
Volume 10, Issue 3, pages 511–520, November 1993
How to Cite
Swift, S., Winson, M. K., Chan, P. F., Bainton, N. J., Birdsall, M., Reeves, P. J., Rees, C. E. D., Chhabra, S. R., Hill, P. J., Throup, J. P., Bycroft, B. W., Salmond, G. P. C., Williams, P. and Stewart, G. S. A. B. (1993), A novel strategy for the isolation of luxl homologues: evidence for the widespread distribution of a LuxR:Luxl superfamily in enteric bacteria. Molecular Microbiology, 10: 511–520. doi: 10.1111/j.1365-2958.1993.tb00923.x
- Issue published online: 27 OCT 2006
- Article first published online: 27 OCT 2006
- Received 21 December, 1992; revised 25 May, 1993; accepted 16 July, 1993.
The pheromone N-(3-oxohexanoyl)-L-homoserine lactone (OHHL) regulates expression of bioluminescence in the marine bacterium Vibrio fischeri, the production of carbapenem antibiotic in Erwinia carotovora and exoenzymes in both E. carotovora and Pseudomonas aeruginosa. A characteristic feature of this regulatory mechanism in V. fischeri is that it is cell density-dependent, reflecting the need to accumulate sufficient pheromone to trigger the induction of gene expression. Using a lux plasmid-based bioluminescent sensor for OHHL, pheromone production by E. carotovora, Enterobacter agglomerans, Hafnia alvei, Rahnella aquatilis and Serratia marcescens has been demonstrated and shown also to be cell density-dependent. Production of OHHL implies the presence in these bacteria of a gene equivalent to luxl. Chromosomal banks from all five enteric bacteria have yielded clones capable of eliciting OHHL production when expressed in Escherichia coli. The luxl homologue from both E. carotovora (carl) and E. agglomerans (eagl) were characterized at the DNA sequence level and the deduced protein sequences have only 25% identity with the V. fischeri Luxl. Despite this, carl, eagl and luxl are shown to be biologically equivalent. An insertion mutant of eagl demonstrates that this gene is essential for OHHL production in E. agglomerans.