Objective: In this paper, we have introduced topoisomerase inhibitors, mechanism of action and types of them. DNA topoisomerases are ubiquitous enzymes that catalyze essential enzymes to solve the topological problems accompanying key nuclear processes such as DNA replication, transcription, repair and chromatin assembly by introducing temporary single or double strand breaks in the DNA. Result...

A series of biochemical assays were developed and performed to monitor the molecular events that occur during the Hin-mediated DNA inversion reaction. These events can be divided into five different stages: 1) binding of proteins (Hin, Fis, and HU) to DNA; 2) pairing of Hin-binding sites; 3) invertasome formation; 4) DNA strand cleavage; 5) strand rotation and religation. A series of topoisomer...

We show that, despite differences in primary structure, substrate preference, and mechanism of catalysis, yeast DNA topoisomerase I can functionally substitute for Escherichia coli DNA topoisomerase I. A family of plasmids expressing the yeast TOP1 gene or 5'-deletion mutations of it were used to complement the temperature-sensitive phenotype of an E. coli topA mutant. These plasmids were then ...

Although our knowledge of chromatin organization has advanced significantly in recent years, much about the relationships between different features of genome architecture is still unknown. Folding of mammalian genomes into spatial domains is thought to depend on architectural proteins, other DNA-binding proteins, and different forms of RNA. In addition, emerging evidence points towards the pos...

The short supercoiled circular DNA molecules are shown to be glassy systems and canonical Metropolis Monte Carlo simulations of the systems tend to get stuck in local metastable energy basins. A novel Monte Carlo algorithm is developed to alleviate the problem of “ergodicity breaking” of the glassy systems, in which the Markov process is driven by an explicitly analytic weight factor with enhan...

In the present study, we show in vitro binding of PrrA, a global regulator in Rhodobacter sphaeroides 2.4.1, to the PrrA site 2, within the RSP3361 locus. Specific binding, as shown by competition experiments, requires the phosphorylation of PrrA. The binding affinity of PrrA for site 2 was found to increase 4- to 10-fold when spermidine was added to the binding reaction. The presence of extrac...