title: A solo luxI-type gene directs acylhomoserine lactone synthesis and contributes to motility control in the marine sponge symbiont Ruegeria sp. KLH11.
abstract: Marine sponges harbour abundant and diverse bacterial communities, providing an ideal environment for bacterial cell-density-dependent cell-cell signalling, termed quorum sensing. The marine sponge symbiont Ruegeria sp. KLH11 produces mainly long chain acylhomoserine lactones (AHLs) and has been developed as a quorum sensing model for roseobacterial sponge symbionts. Two pairs of luxR/I homologues were identified by genetic screening and were designated ssaRI and ssbRI (sponge-associated symbiont locus A or B, luxR/luxI homologue). In this study, we identified a third luxI-type gene, named sscI. The sscI gene does not have a cognate luxR homologue present at an adjacent locus and thus sscI is an AHL synthase solo. The sscI gene is required for production of long-chain hydroxylated AHLs, contributes to AHL pools and modestly influences flagellar motility in KLH11. A triple mutant for all luxI-type genes cannot produce AHLs, but still synthesizes para-coumaroyl-homoserine lactone.
authors.affiliation: Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, 701 East Pratt Street, Baltimore, MD 21202, USA.
authors.forename: Jindong
authors.initials: J
authors.lastname: Zan
authors.affiliation: Department of Biology, 1001 East 3rd Street, Jordan Hall 142, Indiana University, Bloomington, IN 47405, USA.
authors.forename: Okhee
authors.initials: O
authors.lastname: Choi
authors.affiliation: Department of Pharmacology, School of Medicine, University of Colorado Denver, 12801 East 17th Avenue, Aurora, CO 80045, USA.
authors.forename: Hiruy
authors.initials: H
authors.lastname: Meharena
authors.affiliation: Department of Pharmacology, School of Medicine, University of Colorado Denver, 12801 East 17th Avenue, Aurora, CO 80045, USA.
authors.forename: Charis L
authors.initials: CL
authors.lastname: Uhlson
authors.affiliation: Department of Pharmacology, School of Medicine, University of Colorado Denver, 12801 East 17th Avenue, Aurora, CO 80045, USA.
authors.forename: Mair E A
authors.initials: MEA
authors.lastname: Churchill
authors.affiliation: Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, 701 East Pratt Street, Baltimore, MD 21202, USA.
authors.forename: Russell T
authors.initials: RT
authors.lastname: Hill
authors.affiliation: Department of Biology, 1001 East 3rd Street, Jordan Hall 142, Indiana University, Bloomington, IN 47405, USA.
authors.forename: Clay
authors.initials: C
authors.lastname: Fuqua
mesh_terms: D054742:Acyl-Butyrolactones / Q000378:metabolism*; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D023061:Gene Order; D056426:Genetic Loci; D009154:Mutation; D011161:Porifera / Q000382:microbiology*; D041902:Rhodobacteraceae / Q000235:genetics* / Q000378:metabolism*; D013559:Symbiosis; D014157:Transcription Factors / Q000235:genetics*
chemical_list: D054742:Acyl-Butyrolactones; D001426:Bacterial Proteins; C085427:LuxI protein, Bacteria; D014157:Transcription Factors