Within the phylum Bacteroidetes, the gyrB gene, encoding for the B subunit of the DNA gyrase, has been used as a phylogenetic marker for several genera closely related to Flavobacterium. The phylogenies of the complete 16S rRNA gene and the gyrB gene were compared for 33 Antarctic Flavobacterium isolates and 23 type strains from closely related Flavobacterium species. gyrB gene sequences provid...

The cloning and characterization of DNA gyrase genes from Mycobacterium smegmatis is described. The DNA sequence of 5119 bp encoding both gyrB and gyrA genes was determined. The gene gyrB precedes gyrA with a short intergenic region of 29 nucleotides. The proteins encoded, GyrB and GyrA, exhibit 45-80% identity to gyrase polypeptides from other bacteria. The genes were further engineered for ov...

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 incompati...

We report the cloning of the gyrB gene from Streptococcus pneumoniae 533 that carries the nov-1 allele. The gyrB gene codes for a protein homologous to the gyrase B subunit of archaebacteria and eubacteria. The same amino acid substitution (Ser-127 to Leu) confers novobiocin resistance on four isolates of S. pneumoniae. This amino acid position is equivalent to Val-120 of Escherichia coli GyrB,...

DNA gyrase is the only enzyme known to negatively supercoil DNA. The enzyme is a heterotetramer of A(2)B(2) subunit composition. Alignment of the primary sequence of gyrase B (GyrB) from various species shows that they can be grouped into two classes. The GyrB of Gram-negative eubacteria has a stretch of about 165 amino acids in the C-terminal half, which is lacking in other GyrB subunits and t...

The phylogenetic relationships of all known species of the genus Aeromonas, and especially Aeromonas bestiarum and Aeromonas salmonicida, were investigated on 70 strains using the rpoD sequence, which encodes the sigma70 factor. This analysis was complemented with the sequence of gyrB, which has already proven useful for determining the phylogenetic relationships in the genus. Nucleotide sequen...

Viridans group streptococci (VGS) are a heterogeneous group of medically important bacteria that cannot be accurately assigned to a particular species using conventional phenotypic methods. Although multilocus sequence analysis (MLSA) is considered the gold standard for VGS species-level identification, MLSA is not yet feasible in the clinical setting. Conversely, molecular methods, such as sod...

GroEL protein and groEL mRNA transcript were up-regulated in gyrB mutants of Borrelia burgdorferi, a causative agent of Lyme disease. Furthermore, the protein and transcript levels in gyrB mutants were greater than those in experimentally heat-shocked cultures of wild-type B. burgdorferi. Circular DNA in the gyrB mutants was more relaxed than in wild-type cells, although groEL is on the linear ...

Bacterial strains were isolated from sponge and green algae which were collected on the coast of Japan and Palau. The phylogenetic relationships of these isolates among marine species of the Cytophaga-Flavobacterium-Bacteroides complex were analysed by using their gyrB nucleotide sequences and translated peptide sequences (GyrB) in addition to 16S rDNA sequences. These isolates were closely rel...