Genetic characterization of ompH mutants in the deep-sea bacterium Photobacterium sp. strain SS9.
OmpH is an outer membrane protein produced by the deep-sea bacterium Photobacterium species strain SS9 in response to elevated hydrostatic pressure. In order to facilitate studies of the function of this protein, a series of OmpH+ and OmpH- strains were obtained from SS9 by Tn5 gene replacement mutagenesis. A previously isolated ompH::lacZ strain and a derivative of this strain harboring a plasmid expressing the wild-type ompH gene were also utilized. The acridine mutagen ICR 191 preferentially inhibited the growth of OmpH+ over OmpH- cells. Indeed, OmpH+ cultures treated with the mutagen rapidly accumulated mutants producing reduced levels of OmpH. In addition, OmpH+ cells took up the peptide Met-Leu-Phe approximately 15 times more rapidly than OmpH- cells. The results are consistent with the hypothesis that OmpH functions as a relatively large, nonspecific diffusion channel.
Center for Marine Biomedicine and Biotechnology, Scripps Institution of Oceanography, University of California, La Jolla 92093-0202.
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D000585:Aminacrine / Q000031:analogs & derivatives / Q000494:pharmacology; D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000502:physiology*; D008969:Molecular Sequence Data; D009154:Mutation; D009588:Nitrogen Mustard Compounds / Q000494:pharmacology; D010776:Photobacterium / Q000187:drug effects / Q000235:genetics*; D018272:Porins / Q000235:genetics
D001425:Bacterial Outer Membrane Proteins; D009588:Nitrogen Mustard Compounds; D018272:Porins; C067128:ompH protein, bacteria; D000585:Aminacrine; C004294:acridine half-mustard