title: Spontaneous mutations in gas vesicle genes of Planktothrix spp. affect gas vesicle production and critical pressure.
abstract: Wild-type strains of the cyanobacterium Planktothrix rubescens have a cluster of gas vesicle (gvp) genes with repeats of alternating gvpA and gvpC. The gvpC occurs in three length variants, all with the same 3'-sequence, OmegaC. Spontaneous non-buoyant mutants had lost some of the alternating gvpAC copies and their gvpC genes had a novel 3'-end sequence, PsiC; additional gvpC genes terminating in this sequence were also found in the wild-type and representatives of other GV genotypes. Alleles of gvpC terminating in PsiC occurred only at the downstream ends of the gvpAC clusters investigated; all other gvpCs terminated in OmegaC. Mutants of strains with the GV3 genotype produced only 30-50% of the gas vesicles present in the wild-type; their gas vesicles had lower mean critical pressures (0.70-0.78 MPa) than those in the wild-type (1.05-1.10 MPa).
authors.affiliation: School of Biological Sciences, University of Bristol, Woodland Road, UK.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Beard
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Handley
authors.forename: Anthony E
authors.initials: AE
authors.lastname: Walsby
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D003470:Culture Media; D000458:Cyanobacteria / Q000235:genetics / Q000502:physiology*; D005740:Gases; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D011312:Pressure; D011506:Proteins; D017422:Sequence Analysis, DNA; D014617:Vacuoles / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media; D005740:Gases; C076193:GvpC protein, Anabaena flos-aquae; D008565:Membrane Proteins; D011506:Proteins; C038524:gas vesicle protein