Topoisomerases are ubiquitous enzymes necessary for controlling the interlinking and twisting of DNA molecules. Among the four topoisomerases identified in eubacteria, two, DNA gyrase and topoisomerase IV have been exploited by nature and the pharmaceutical industry as antibacterial targets. Natural products that are inhibitors of one or both of these topoisomerases include the coumarin and cyc...

PprA, a radiation-induced Deinococcus-specific protein, was previously shown to be required for cell survival and accurate chromosome segregation after exposure to ionizing radiation. Here, we used an in vivo approach to determine, by shotgun proteomics, putative PprA partners coimmunoprecipitating with PprA when cells were exposed to gamma rays. Among them, we found the two subunits of DNA gyr...

Antibiotics targeting DNA gyrase have been a clinical success story for the past half-century, and the emergence of bacterial resistance has fueled the search for new gyrase inhibitors. In this paper we demonstrate that a new class of gyrase inhibitors, the gyramides, are bacteriostatic agents that competitively inhibit the ATPase activity of Escherichia coli gyrase and produce supercoiled DNA ...

We have identified a topoisomerase activity from Escherichia coli related to DNA gyrase (topoisomerase II): we designate it topoisomerase II'. It was constructed of two subunits, which were purified separately. One is the product of the gyrA (formerly nalA) gene and is identical to subunit A of DNA gyrase. The other is a 50,000-dalton protein, which we have purified to homogeneity and call v. v...

Although bacterial gyrase and topoisomerase IV have critical interactions with positively supercoiled DNA, little is known about the actions of these enzymes on overwound substrates. Therefore, the abilities of Bacillus anthracis and Escherichia coli gyrase and topoisomerase IV to relax and cleave positively supercoiled DNA were analyzed. Gyrase removed positive supercoils ∼10-fold more rapidly...

DNA gyrase is a remarkable enzyme, catalysing the seemingly complex reaction of DNA supercoiling. As gyrase is essential in prokaryotes, it is a good target for antibacterial agents. These agents have diverse chemical structures and interact with gyrase in a variety of ways.

Quinolones inhibit bacterial type II DNA topoisomerases (e.g. DNA gyrase) and are among the most important antibiotics in current use. However, their efficacy is now being threatened by various plasmid-mediated resistance determinants. Of these, the pentapeptide repeat-containing (PRP) Qnr proteins are believed to act as DNA mimics and are particularly prevalent in gram-negative bacteria. Predi...

Enteric fever is a major cause of morbidity in several parts of the Indian subcontinent. The treatment for typhoid fever majorly includes the fluoroquinolone group of antibiotics. Excessive and indiscriminate use of these antibiotics has led to development of acquired resistance in the causative organism Salmonella Typhi. The resistance towards fluoroquinolones is associated with mutations in t...

A paucity of novel acting antibacterials is in development to treat the rising threat of antimicrobial resistance, particularly in Gram-negative hospital pathogens, which has led to renewed efforts in antibiotic drug discovery. Fluoroquinolones are broad-spectrum antibacterials that target DNA gyrase by stabilizing DNA-cleavage complexes, but their clinical utility has been compromised by resis...