Nalidixic acid resistance: A second genetic character involved in DNA gyrase activity

Gellert, Martin; Mizuuchi, Kiyoshi; O’Dea, Mary H.; Itoh, Tateo; Tomizawa, Jun-ichi

doi:10.1073/pnas.74.11.4772

Cited by 780 publications

(552 citation statements)

References 16 publications

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“…This design is vital for the cell because the torsional tension of supercoiled DNA is an important reservoir of free energy, which helps to drive all processes requiring the melting of DNA strands, such as transcription [Lim et al, 2003;Peter et al, 2004], replication [Funnell et al, 1986], and recombination [Nash, 1990]. The relevance of limiting the spread of relaxation is underlined by the fact that even slight changes in the overall superhelicity of the chromosome are lethal [Gellert et al, 1976[Gellert et al, , 1977. Short distances between domain boundaries might, in addition, facilitate the repair of double-strand breaks because they restrict the movement of the two ends to be joined.…”

Section: Topological Structure Of the Chromosomementioning

confidence: 99%

The bacterial nucleoid: A highly organized and dynamic structure

Thanbichler

Wang

Shapiro

2005

J of Cellular Biochemistry

120

101

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Recent advances in bacterial cell biology have revealed unanticipated structural and functional complexity, reminiscent of eukaryotic cells. Particular progress has been made in understanding the structure, replication, and segregation of the bacterial chromosome. It emerged that multiple mechanisms cooperate to establish a dynamic assembly of supercoiled domains, which are stacked in consecutive order to adopt a defined higher-level organization. The position of genetic loci on the chromosome is thereby linearly correlated with their position in the cell. SMC complexes and histone-like proteins continuously remodel the nucleoid to reconcile chromatin compaction with DNA replication and gene regulation. Moreover, active transport processes ensure the efficient segregation of sister chromosomes and the faithful restoration of nucleoid organization while DNA replication and condensation are in progress.

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Section: Topological Structure Of the Chromosomementioning

confidence: 99%

The bacterial nucleoid: A highly organized and dynamic structure

Thanbichler

Wang

Shapiro

2005

J of Cellular Biochemistry

120

101

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“…As a result, quinolone concentrations sufficient to block replication do not relax chromosomal DNA supercoiling (29). When the quinolone is removed, the breaks are readily resealed (11,31) and the inhibitory effects of the compounds are reversed (13,21,27). Irreversible events that lead to rapid cell death occur at higher quinolone concentrations (1,20).…”

mentioning

confidence: 99%

Effect of Anaerobic Growth on Quinolone Lethality with Escherichia coli

Malik¹,

Hussain²,

Drlica³

2007

Antimicrob Agents Chemother

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Quinolone activity against Escherichia coli was examined during aerobic growth, aerobic treatment with chloramphenicol, and anaerobic growth. Nalidixic acid, norfloxacin, ciprofloxacin, and PD161144 were lethal for cultures growing aerobically, and the bacteriostatic activity of each quinolone was unaffected by anaerobic growth. However, lethal activity was distinct for each quinolone with cells treated aerobically with chloramphenicol or grown anaerobically. Nalidixic acid failed to kill cells under both conditions; norfloxacin killed cells when they were grown anaerobically but not when they were treated with chloramphenicol; ciprofloxacin killed cells under both conditions but required higher concentrations than those required with cells grown aerobically; and PD161144, a C-8-methoxy fluoroquinolone, was equally lethal under all conditions. Following pretreatment with nalidixic acid, a shift to anaerobic conditions or the addition of chloramphenicol rapidly blocked further cell death. Formation of quinolone-gyrase-DNA complexes, observed as a sodium dodecyl sulfate (SDS)-dependent drop in cell lysate viscosity, occurred during aerobic and anaerobic growth and in the presence and in the absence of chloramphenicol. However, lethal chromosome fragmentation, detected as a drop in viscosity in the absence of SDS, occurred with nalidixic acid treatment only under aerobic conditions in the absence of chloramphenicol. With PD161144, chromosome fragmentation was detected when the cells were grown aerobically and anaerobically and in the presence and in the absence of chloramphenicol. Thus, all quinolones tested appear to form reversible bacteriostatic complexes containing broken DNA during aerobic growth, during anaerobic growth, and when protein synthesis is blocked; however, the ability to fragment chromosomes and to rapidly kill cells under these conditions depends on quinolone structure.When DNA topoisomerases bind to bacterial DNA, they form complexes that are trapped by the quinolone antibacterials (for a review, see reference 6). These ternary drug-enzyme-DNA complexes block DNA replication (5, 27, 29, 32), RNA synthesis (22, 33), and cell growth (2, 12). A key feature of the complexes is that the trapped DNA moiety is broken, with its ends constrained through covalent linkage to the GyrA protein (24, 25). As a result, quinolone concentrations sufficient to block replication do not relax chromosomal DNA supercoiling (29). When the quinolone is removed, the breaks are readily resealed (11, 31) and the inhibitory effects of the compounds are reversed (13,21,27). Irreversible events that lead to rapid cell death occur at higher quinolone concentrations (1, 20). We have proposed that rapid cell death arises from chromosome fragmentation that occurs when doublestrand DNA breaks are released from the protein-mediated constraint present in ternary complexes. At rapidly lethal quinolone concentrations, supercoils cannot be maintained (1) and fragmented DNA is obtained under conditions that allow resealing at bacteriost...

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“…Such enzymes have been found widely in nature and, in general, their function is unknown. The exception is DNA gyrase, an enzyme that introduces negative superhelical turns into relaxed closed circular DNA by coupling a nicking-closing activity to an ATPase (9,10). Possible roles for topoisomerases in transcription, replication, and recombination have been proposed (7,8).…”

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confidence: 99%

Nicking-closing activity associated with bacteriophage lambda int gene product.

Kikuchi¹,

Nash²

1979

Proc. Natl. Acad. Sci. U.S.A.

165

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Integrative recombination of bacteriophage X requires the action of the protein Int, the product of the phage int gene. In this paper we show that highly purified Int relaxes supercoiled DNA. The association of this nicking-closing activity with Int is shown by: (i) the cosedimentation o nicking-closing and recombination activities of purified Int, (ii) the parallel inactivation of the two activities in purified Int by both heat and a specific antiserum, and (iii) the alteration of both activities in crude extracts of a strain expressing a mutant int gene. The nicking-closing activity of Int functions in the absence of divalent cations and in the absence of an apparent source of chemical energy. The activity displays no obvious sequence specificity and is inhibited by Mg +, spermidine, and singlestranded DNA. Int relaxes positive as well as negative supercoils. We present a model for the mechanism of strand exchange that describes how the nicking-closing activity of Int might be used during recombination. Bacteriophage X forms lysogens of Escherichia coli by integrating viral DNA into the bacterial chromosome (reviewed in ref. 1). The integration occurs as a result of a reciprocal recombination between specific genetic loci, the viral and bacterial attachment sites (attP and attB, respectively). Integrative recombination readily takes place in a cell-free system (2), and the in vitro reaction has been used to characterize the overall pathway of this recombination. Briefly, it has been shown that DNA supercoiling is essential for recombination: at least attP must be located on a negatively supertwisted circle of DNA (3,4). Given an appropriately supertwisted substrate, the only low molecular weight substances required for full recombination activity are spermidine, KC1, and buffer. The products of integrative recombination are a reciprocal pair of continuous double-helical DNAs. This fact and the simplicity of the cofactor requirements suggest that recombination occurs by a very conservative mechanism-i.e., one that involves-no degradation or resynthesis of DNA and one that retains the bond energy of the phosphodiester backbone during breakage and reunion.In vitro integrative recombination has been used to assay the purification of the proteins involved in this reaction. We have previously reported the purification to near homogeneity of the X int gene product, the only virus-coded component of the integration system (5, 6). We showed that, in addition to supertwisted substrate DNA and the cofactors described above, purified int gene product (Int) requires the participation of protein(s) encoded by the bacterial host in order to carry out integrative recombination. In the absence of this host component and spermidine, highly purified Int binds to DNA, forming specific stable complexes with DNA containing attP. Thus, Int is a specificity element for integrative recombination, recognizing at least one of the two recombining sites. We now report that, in the absence of the other components of the recombinati...

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Nalidixic acid resistance: A second genetic character involved in DNA gyrase activity

Cited by 780 publications

References 16 publications

The bacterial nucleoid: A highly organized and dynamic structure

The bacterial nucleoid: A highly organized and dynamic structure

Effect of Anaerobic Growth on Quinolone Lethality with Escherichia coli

Nicking-closing activity associated with bacteriophage lambda int gene product.

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