Genome structure of Halobacterium halobium: plasmid dynamics in gas vacuole deficient mutants.
Halobacterium halobium contains two gas vacuole protein genes that are located in plasmid pHH1 (p-vac) and in the chromosomal DNA (c-vac). The mutation frequency for these genes is different: the constitutively expressed p-vac gene is mutated with a frequency of 10(-2), while the chromosomal gene expressed in the stationary phase of growth is mutated with a frequency of 10(-5). The difference in the mutation susceptibility is due to the dynamics of plasmid pHH1. p-vac gene mutations are caused (i) by the integration of an insertion element or (ii) by a deletion event encompassing the p-vac gene region. In contrast, c-vac mutants analyzed to date incurred neither insertion elements nor deletions. Deletion events within pHH1 occur at high frequencies during the development of a H. halobium culture. The investigation of the fusion regions resulting from deletion events indicates that insertion elements are involved. The analysis of pHH1 deletion variants led to a 4 kilobase pair DNA region containing the origin of replication of the pHH1 plasmid.
Pfeifer
F
F
Max-Planck-Institut für Biochemie, Martinsried, Federal Republic of Germany.
Blaseio
U
U
Horne
M
M
D019843:Archaeal Proteins; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D002872:Chromosome Deletion; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D014644:Genetic Variation; D006217:Halobacterium / Q000235:genetics*; D008565:Membrane Proteins; D009154:Mutation; D010957:Plasmids; D011506:Proteins; D015183:Restriction Mapping
D019843:Archaeal Proteins; D001425:Bacterial Outer Membrane Proteins; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D008565:Membrane Proteins; D011506:Proteins; C038524:gas vesicle protein