Bacillus subtilis deoxyribonucleic acid gyrase

Sugino, Akio; Bott, Kenneth F.

doi:10.1128/jb.141.3.1331-1339.1980

Cited by 73 publications

(17 citation statements)

References 19 publications

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“…Such an arrangement suggests a translational coupling mechanism that could facilitate the production of equimolar amounts of the two subunits that would be required for making a functional enzyme. The genomic organization of gyr genes in many species also suggests an operon-like arrangement (Sugino & Bott 1980;Colman et al 1990;Holmes & Dyall-Smith 1991;Thiara & Cundliffe 1993;Madhusudan et al 1994;Salazar et al 1996). However, it is noteworthy that in Bacillus subtilis, although the gyrA and gyrB genes are near each other, they are transcribed independently (Lampe & Bott 1985).…”

Section: Discussionmentioning

confidence: 99%

Regulation of DNA gyrase operon in Mycobacterium smegmatis: a distinct mechanism of relaxation stimulated transcription

Unniraman

Nagaraja

1999

Genes to Cells

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Background: The topological state of DNA is a result of the diverse influences of various topoisomerases present in the cell. Amongst these, DNA gyrase is the only enzyme that is capable of supercoiling DNA. In all the eubacterial cells tested so far, DNA gyrase has proved to be essential for survival. We have earlier cloned gyr genes from Mycobacterium smegmatis. Unlike the situation in Escherichia coli, genes encoding the two subunits of gyrase are present as a contiguous stretch in the M. smegmatis genome.

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Section: Discussionmentioning

confidence: 99%

Regulation of DNA gyrase operon in Mycobacterium smegmatis: a distinct mechanism of relaxation stimulated transcription

Unniraman

Nagaraja

1999

Genes to Cells

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“…In Bacillus subtilis, gyrase from an NB resistance (novA) mutant or an NA resistance (nalA) mutant is resistant to NB or NA, and both the novA and nalA genes are very close each other in the proximity of the origin of DNA replication (49). The replication origin of chromosomal DNA, oriC, is mapped at about 83 mi in E. coli K-12 (2).…”

Section: Discussionmentioning

confidence: 99%

“…So, the situation ofgyrB and nal-31 in E. coli is very similar to that of novA and nalA in B. subtilis. There is circumstantial evidence that B. subtilis gyrase is involved in the initiation of DNA replication (49). The rapidity of the inhibition of DNA replication by pyridonecarboxylic acid derivatives (43) and counermycin A, (40,41) or by mutational inactivation of the gyrA protein (25, 38) means a role of gyrase or related enzymes in DNA replication but would not rule out their role in the process of initiation of DNA replication.…”

Section: Discussionmentioning

confidence: 99%

New nalidixic acid resistance mutations related to deoxyribonucleic acid gyrase activity

Yamagishi¹,

Furutani²,

Inoue³

et al. 1981

J Bacteriol

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In Escherichia coli K-12 mutants which had a new nalidixic acid resistance mutation at about 82 min on the chromosome map, cell growth was resistant to or hypersusceptible to nalidixic acid, oxolinic acid, piromidic acid, pipemidic acid, and novobiocin. Deoxyribonucleic acid gyrase activity as tested by supercoiling of A phage deoxyribonucleic acid inside the mutants was similarly resistant or hypersusceptible to the compounds. The drug concentrations required for gyrase inhibition were much higher than those for cell growth inhibition but similar to those for inhibition of A phage multiplication. Transduction analysis with A phages carrying the chromosomal fragment of the tnaA-gyrB region suggested that one of the mutations, nal-31, was located on the gyrB gene.Nalidixic acid (NA) (27), oxolinic acid (OA) (24), piromidic acid (PA) (34), and pipemidic acid (PPA) (29) are synthetic antibacterial compounds having a pyridonecarboxylic acid moiety as a common chemical structure and are mainly active against gram-negative bacteria (9,43,45,46). These compounds specifically inhibit bacterial DNA synthesis with little effect on RNA and protein synthesis around their miniimal inhibitory concentrations (6,43). The inhibition of DNA synthesis is so rapid that the compounds are considered to act during the elongation of DNA chains (6, 10).Recently, two research groups found that NA and OA inhibited an enzyme called DNA gyrase (15,50). This enzyme introduces negative superhelical turns into duplex DNA (16) and is considered to play an important role in metabolic processes involving DNA (7,25,38). Gyrase from Escherichia coli consists of two subunits, A and B (20). Subunit A is a homodimer of a 105,000dalton protein encoded by the gyrA (formerly nalA) gene, which determines resistance to NA, and subunit B consists of a 95,000-dalton protein encoded by the gyrB (formerly cou) gene, which determines resistance to novobiocin (NB) and coumermycin Al (20,35). Subunit A from an NA-resistant gyrA mutant and subunit B from a coumermycin Ar-resistant gyrB mutant each reconstitute a gyrase with the expected drug resistance. The gyrA gene is located at approximately 48 min, and the gyrB gene is at approximately 82 min on the genetic map of Escherichia coli K-12 (2). Cross-resistance is usually observed among pyridonecarboxylic acid derivatives, but it is so incomplete that bacteria which are highly re-sistant to NA are inhibited by some of them, e.g., PPA, at relatively low concentrations (46). During a study on the mode of incomplete crossresistance, two new types of NA resistance mutations were found at about 82 min, i.e., nal-21 and nal-31 (formerly naiC), and nal-24 (formerly nalD) (22). The nal-21 or nal-31 mutation caused resistance to NA and PA but also hypersusceptibility to PPA. The nal-24 mutation, like NA resistance gyrA mutations, conferred resistance to all three drugs. The nal-21, nal-31, and nal-24 mutations were no more resistant to NB by a conventional agar dilution method for the determination of miniimal inhibitory ...

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“…We have previously shown that S. aureus gyrA is located on the SmaI G fragment, a fragment that also contains the nov locus, which encodes resistance to novobiocin (51). Novobiocin and coumermycin resistance is caused by mutations in gyrB in other species (11,46,47), and in S. aureus, gyrB and gyrA are contiguous genes (15,28). Thus, we postulated that nov, which is a selectable marker in S. aureus, would be tightly linked to gyrA.…”

Section: Localization Of Grlb and Grla On The S Aureus Chromosomementioning

confidence: 99%

Quinolone resistance mutations in topoisomerase IV: relationship to the flqA locus and genetic evidence that topoisomerase IV is the primary target and DNA gyrase is the secondary target of fluoroquinolones in Staphylococcus aureus

Trucksis

Hooper

1996

Antimicrob Agents Chemother

218

122

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Mutations in the flqA (formerly ofx/cfx) resistance locus of Staphylococcus aureus were previously shown to be common after first-step selections for resistance to ciprofloxacin and ofloxacin and to map on the S. aureus chromosome distinctly from gyrA, gyrB, and norA.grlA and grlB, the genes for the topoisomerase IV of S. aureus, were identified from a genomic lambda library on a common KpnI fragment, and grlB hybridized specifically with the chromosomal SmaI A fragment, which contains the flqA locus. Amplification of grlA sequences (codons 1 to 251) by PCRs from nine independent single-step flqA mutants, one multistep mutant, and the parent strain identified mutations encoding a change from Ser to Phe at position 80 in four mutants, a novel change from Ala to either Glu or Pro at position 116 in three mutants, and no change in three mutants. In the multistep mutant, another resistance locus, flqC, was mapped by transformation to the chromosomal SmaI G fragment by linkage to omega(ch::Tn551)1051 (58%) and nov (97.9%), which encodes resistance to novobiocin. This fragment contains the gyrA gene, and flqC mutants had a mutation in gyrA encoding a change from Ser to Leu at position 84, a change previously found in resistant clinical isolates. In genetic outcrosses, the flqC (gyrA) mutation expressed resistance only in flqA mutants, including those with both types of grla mutations. The silent mutant allele of gyrA was present in a flqA background and expressed resistance only upon introduction of a grlA mutation. At fourfold the MIC of ciprofloxacin, the bactericidal activity of ciprofloxacin was reduced in a grlA mutant and was abolished in gyrA grlA double mutants. These findings provide direct genetic evidence that topoisomerase IV is the primary target of current fluoroquinolones in S. aureus and that this effect may result from the greater sensitivity of topoisomerase IV relative to that of DNA gyrase to these agents. Furthermore, resistance from an altered DNA gyrase requires resistant topoisomerase IV for its expression.

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Bacillus subtilis deoxyribonucleic acid gyrase

Cited by 73 publications

References 19 publications

Regulation of DNA gyrase operon in Mycobacterium smegmatis: a distinct mechanism of relaxation stimulated transcription

Regulation of DNA gyrase operon in Mycobacterium smegmatis: a distinct mechanism of relaxation stimulated transcription

New nalidixic acid resistance mutations related to deoxyribonucleic acid gyrase activity

Quinolone resistance mutations in topoisomerase IV: relationship to the flqA locus and genetic evidence that topoisomerase IV is the primary target and DNA gyrase is the secondary target of fluoroquinolones in Staphylococcus aureus

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