title: A Lux-like quorum sensing system in the extreme acidophile Acidithiobacillus ferrooxidans.
abstract: The genome of the acidophilic, proteobacterium Acidithiobacillusferrooxidans, contains linked but divergently oriented genes, termed afel and afeR, whose predicted protein products are significantly similar to the LuxI and LuxR families of proteins. A possible promoter and Lux box are predicted upstream of afel. A cloned copy of afel, expressed in E. coli, encodes an enzyme that catalyzes the production of a diffusible compound identified by gas chromatography and mass spectrometry as an unsubstituted N-acyl homoserine lactone (AHL) of chain length C14. This AHL can be detected by a reporter strain of Sinorhizobium meliloti Rm41 suggesting that it is biologically active. The reporter strain also responds to extracts of the supernatant of A. ferrooxidans grown to early stationary phase in sulfur medium indicating that a diffusible AHL is produced by this microorganism. Semi-quantitative RT-PCR experiments indicate that afeI and afeR are expressed maximally in early stationary phase and are more expressed when A. ferrooxidans is grown in sulfur--rather than iron-containing medium. Given the predicted amino acid sequence and functional properties of AfeI and AfeR it is proposed that A. ferrooxidans has a quorum sensing system similar to the LuxI-LuxR paradigm.
authors.affiliation: Institute of Cellular and Molecular Biology (ICBM), University of Chile, Santiago, Chile.
authors.forename: Mariella
authors.initials: M
authors.lastname: Rivas
authors.forename: Michael
authors.initials: M
authors.lastname: Seeger
authors.forename: David S
authors.initials: DS
authors.lastname: Holmes
authors.forename: Eugenia
authors.initials: E
authors.lastname: Jedlicki
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000235:genetics; D042763:Acidithiobacillus / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002265:Carboxylic Ester Hydrolases / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D011401:Promoter Regions, Genetic / Q000235:genetics; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; C085427:LuxI protein, Bacteria; D012097:Repressor Proteins; D015534:Trans-Activators; D014157:Transcription Factors; C064778:LuxR autoinducer binding proteins; C088386:homoserine lactone; D002265:Carboxylic Ester Hydrolases; C432003:N-acyl homoserine lactonase; D015107:4-Butyrolactone