Kato S, Kikuchi A
Laboratory of Medical Mycology, Nagoya University School of Medicine.
Nagoya J Med Sci. 1998 May;61(1-2):11-26.
DNA is a macromolecule carrying all genetic information and it must be packed in the cell nucleus. DNA is a double helix where one strand coils around the other. The helix is unwound and rewound every now and then to take out its information, which requires local alteration of the helical structure, resulting in the super-coiling of DNA. For replication, all the coils must be unwound at least once, and two daughter molecules are often catenated to each other. To solve these problems caused by the helical structure of DNA, topoisomerase activity introducing the transient breaking and rejoining of DNA strand is essential to perform each DNA transaction. In this article, we first review the mechanistic aspect of topoisomerase activity, and then discuss its basic clinical importance.
DNA是一种携带所有遗传信息的大分子，它必须被包装在细胞核中。DNA是一种双螺旋结构，其中一条链缠绕在另一条链上。螺旋会不时地解开和重新缠绕以提取其信息，这需要局部改变螺旋结构，从而导致DNA超螺旋。在复制过程中，所有的螺旋必须至少解开一次，并且两个子分子常常相互连环。为了解决由DNA螺旋结构引起的这些问题，引入DNA链瞬时断裂和重新连接的拓扑异构酶活性对于进行每一次DNA交易至关重要。在本文中，我们首先回顾拓扑异构酶活性的机制方面，然后讨论其基本的临床重要性。
