DNA拓扑异构酶Ⅱ与ⅠA的进化分析  

Evolutionary Analyses of DNA Topoisomerases Ⅱ and ⅠA

作　　者：任永明[1,2] 唐素妮[1,2] 黄京飞[1,3] 

机构地区：[1]中国科学院昆明动物研究所细胞与分子进化重点实验室 [2]中国科学院研究生院,北京100049 [3]中国科学院昆明动物研究所云南省畜禽分子生物学重点实验室,云南昆明650223

出　　处：《Zoological Research》2006年第6期595-600,共6页动物学研究（英文）

基　　金：国家自然科学基金资助项目(30470939和30021004)

摘　　要：DNA拓扑异构酶与断开DNA链和改变其拓扑结构有关。先前的研究认为,拓扑异构酶TypeⅡB是由TypeⅡA通过基因的复制、重组和缺失所造成。然而,本研究结果则显示,TypeⅠA与TypeⅡB的进化关系较近,而TypeⅡA与TypeⅡB的关系较远。因此,TypeⅡB可能是由TypeⅠA演化而来,或者说,TypeⅡB是TypeⅠA在古细菌中的特化形式;TypeⅡB可能是由TypeⅡA通过形成TypeⅠA后演化而成的,而不是由TypeⅡA直接通过基因的复制、重组和缺失所造成。在由TypeⅡA演化成为TypeⅠA,最后演化为TypeⅡB的过程中,DNA拓扑异构酶的催化机制也发生了变化从需要金属离子的协助,演化到了不需要镁离子的存在协助其催化。DNA strand scission and topology changes are catalyzed by DNA topoisomerases. Previous studies suggest that Type ⅡB topoisomerase evolved from Type Ⅱ A by gene duplication, recombination and absence. However, this study shows that the evolutionary relationship between TypeⅠ A and Ⅱ B is closer than that between Type Ⅱ A and ⅡB. Thus, Type Ⅱ B is possibly from Type Ⅰ A, or Type ⅡB is a special form ofⅠ A in arehaebacteria; Type Ⅱ B is probably evolved from Ⅱ A via ⅠA rather than from Ⅱ A directly. During the evolution of Ⅱ A to Ⅱ B via Ⅰ A, the catalytic mechanisms of DNA topoisomerases have also been changed ; that is, metal ions are necessary in the catalyses for beth Ⅰ A and Ⅱ A, but no ion is needed for Ⅱ B.

关 键 词：DNA拓扑异构酶 CAP-like结构域 Toprim结构域 分子进化 催化机制 

分 类 号：Q349[生物学—遗传学]