Catalytic function of DNA topoisomerase II

✍ Scribed by Neil Osheroff; E. Lynn Zechiedrich; Kevin C. Gale

• Publisher: John Wiley and Sons
• Year: 1991
• Tongue: English
• Weight: 845 KB
• Volume: 13
• Category: Article
• ISSN: 0265-9247
• DOI: 10.1002/bies.950130603

✦ Synopsis

Although the genetic code is defined by a linear array of nucleotides, it is the three-dimensional structure of the double helix that regulates most of its cellular functions. Over the past two decades, it has hecome increasingly clear that aspects of this three-dimensionality which reflect topological relationships within the double helix (i.e., superhelical twisting, knotting, or tangling) influence virtually every facet of nucleic acid physiology. In vivo, DNA topology is modulated by ubiquitous enzymes known as topoisomerases. The type I1 enzyme is essential to the eukaryotic cell and is required for unlinking daughter chromosomes and maintaining chromosome structure. Moreover, topoisomerase I1 also has been identified as the primary cellular target for several widely used antineoplastic drugs. Before the physiological functions of topoisomerase 11 can be effectively dissected or its drug interactions fully exploited, it is imperative to understand the mechanism by which this important enzyme carries out its catalytic cycle.