超嗜热菌中逆促旋酶的研究进展  

ADVANCE IN REVERSE GYRASE FROM HYPERTHERMOPHILES

作　　者：王卓华[1] 马辉文[1] 

机构地区：[1]武汉大学生命科学学院微生物系,湖北武汉430070

出　　处：《微生物学杂志》2000年第4期38-41,共4页Journal of Microbiology

摘　　要：逆促旋酶是存在于超嗜热菌的一种能够诱导 ＤＮＡ形成正性超螺旋的ｔｙｐｅⅠ－５’拓扑异构酶。基因测序结果显示其具有典型的二区域结构：位于氨基末端的类解旋酶区与位于羧基末端的拓扑异构酶Ⅰ区。２个区域共同作用催化ＤＮＡ形成正性超螺旋。系统发育学分析表明，目前所有已知的逆促旋酶共同形成了一个ｔｙｐｅⅠ－５’拓扑异构酶的新分支一ＴｏｐＲ。Reverse gyrases exist in hyperthemophiles. They are type I-5' topoisomerases whichenable to induce DNA to form positive superhelixes. Sequencing of the genes encoding reverse gyrase suggested that reverse gyrases are constituted of two distinct domains: a C-terminal domain of an ATP-independent type I topoisomerase and a N-terminal domain of an ATP-inde- pendent helicase-like module. It is believed that positive superhelix is catalyzed by the concerted action of the hdicase module and topoisomerase module in the same polypetide. Phylogenetic analysis shows that all known reverse gyrases so far commonly form a new branch of type I-5' topoisomerase-TopR.

关 键 词：逆促旋酶 正性超螺旋 拓扑异构酶 超嗜热菌 

分 类 号：Q936[生物学—微生物学]