Deletion of the topoisomeraseⅢgene in the hyperthermophilic archaeon Sulfolobus islandicus results in slow growth and defects in cell cycle control

作     者：Xiyang Li Li Guo Ling Deng Deqin Feng Yi Ren Yindi Chu Qunxin She Li Huang 

作者机构：State Key Laboratory of Microbial Resources Institute of Microbiology Chinese Academy of Sciences Beijing 100101 China Archaea Centre Department of Biology Copenhagen University Ole Maalces Vej 5 DK-2200N Copenhagen Denmark 

出 版 物：《Journal of Genetics and Genomics》 (遗传学报（英文版）)

年 卷 期：2011年第38卷第6期

页      面：253-259页

核心收录：

学科分类：0710[理学-生物学] 07[理学] 1001[医学-基础医学(可授医学、理学学位)] 071009[理学-细胞生物学] 070303[理学-有机化学] 0703[理学-化学] 

基　　金：supported by the National Natural Science Foundation of China(Nos.30921065,30730003 and 30870058) to L.Huang the Danish Research Council for Technology and Production(No.274-07-0116) 

主　　题：Hyperthermophilic archaea Sulfolobus islandicus Topoisomerase III topA deletion Phenotype 

摘      要：Topoisomerase III （topo III）, a type IA topoisomerase, is widespread in hyperthermophilic archaea. In order to interrogate the in vivo role of archaeal topo III, we constructed and characterized a topo III gene deletion mutant of Sulfolobus islandicus. The mutant was ,viable but grew more slowly than the wild-type strain, especially in a nutrient-poor medium. Flow cytometry analysis revealed changes of the mutant in growth cycle characteristics including an increase in proportion of cells containing either more than two genome equivalents or less than one genome equivalent in exponentially-growing cultures. As shown by fluorescence microscopy, a fraction of mutant cells in the cultures were drastically enlarged, and at least some of the enlarged cells were apparently capable of resuming cell division. The mutant also shows a different tran- scriptional profile from that of the wild-type strain. Our results suggest that the enzyme may serve roles in chromosomal segregation and control of the level of supercoiling in the cell.