title: Identification and characterization of a putative transcriptional regulator controlling the expression of fouling inhibitors in Pseudoalteromonas tunicata.
abstract: The dark green pigmented marine bacterium Pseudoalteromonas tunicata colonizes living surfaces and produces a range of extracellular compounds that inhibit common fouling organisms, including marine invertebrate larvae, algae, bacteria, and fungi. We have observed a positive correlation between the antifouling activity of P. tunicata strain D2 and the expression of pigmentation. To address the hypothesis that pigmentation and antifouling may be jointly regulated in this organism and to begin to identify potential regulatory elements, we used transposon mutagenesis to generate a strain of P. tunicata deficient in antifouling activity. The data presented here describe the phenotypic and molecular characterization of a nonpigmented transposon mutant strain of P. tunicata (D2W2). Analyses of the antifouling capabilities of D2W2 demonstrate that this strain is deficient in the ability to inhibit each of the target fouling organisms. Genetic analysis of D2W2 identified a gene, designated wmpR (white mutant phenotype), with high sequence similarity to transcriptional regulators ToxR from Vibrio cholerae and CadC from Escherichia coli. Two-dimensional polyacrylamide gel electrophoresis analysis revealed that WmpR is essential for the expression of a significant subset of stationary-phase-induced proteins likely to be important for the synthesis of fouling inhibitors. The identification of a gene involved in the regulation of expression of antifouling phenotypes will contribute to the understanding of the interactions between bacteria and other surface-colonizing organisms in the marine environment.
authors.affiliation: School of Microbiology and Immunology, University of New South Wales, Sydney 2052, New South Wales, Australia.
authors.forename: Suhelen
authors.initials: S
authors.lastname: Egan
authors.forename: Sally
authors.initials: S
authors.lastname: James
authors.forename: Staffan
authors.initials: S
authors.lastname: Kjelleberg
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D001419:Bacteria / Q000254:growth & development; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D003445:Crustacea / Q000254:growth & development; D004251:DNA Transposable Elements; D056890:Eukaryota / Q000254:growth & development; D005658:Fungi / Q000254:growth & development; D020563:Gammaproteobacteria / Q000235:genetics* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D010860:Pigments, Biological / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D017422:Sequence Analysis, DNA; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic; D014561:Urochordata / Q000254:growth & development
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D010860:Pigments, Biological; D014157:Transcription Factors