Identification and characterization of gyrB mutants of Escherichia coli that are defective in partitioning of mini-F plasmids.
hopA mutants, which have been suggested to be defective in mini-F plasmid partitioning (H. Niki, C. Ichinose, T. Ogura, H. Mori, M. Morita, M. Hasegawa, N. Kusukawa, and S. Hiraga, J. Bacteriol. 170:5272-5278, 1988), were found to carry mutations in the gyrB gene, coding for the B subunit of DNA gyrase. In gyrB(HopA) mutants, relaxation of the superhelicity of plasmids, increased IncG incompatibility, and increased SopB protein production were observed. It is suggested that altered expression of the sop genes, which is due to relaxation of the mini-F plasmid DNA, causes both defective partitioning of the mini-F plasmids and increased IncG incompatibility in gyrB(HopA) mutants.
Ogura
T
T
Department of Molecular Genetics, Kumamoto University Medical School, Japan.
Niki
H
H
Mori
H
H
Morita
M
M
Hasegawa
M
M
Ichinose
C
C
Hiraga
S
S
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000032:analysis / Q000235:genetics*; D001483:Base Sequence; D002876:Chromosomes, Bacterial; D003001:Cloning, Molecular; D004250:DNA Topoisomerases, Type II / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D005144:F Factor; D005798:Genes, Bacterial; D005838:Genotype; D046911:Macromolecular Substances; D009154:Mutation; D010957:Plasmids; D015183:Restriction Mapping
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D046911:Macromolecular Substances; C060972:SopB protein, Bacteria; C489223:SopB protein, E coli; C060971:SopA protein, Bacteria; D004250:DNA Topoisomerases, Type II