The relaxing ori-ter balance of Mycoplasma genomes

作     者：ZHENG Xin1 & LIU ShuLin1,2 1 Department of Microbiology, Peking University Health Science Center, Beijing 100083, China 2 Department of Microbiology and Infectious Diseases, University of Calgary, Calgary, T2N 4N1, Canada 

作者机构：Department of Microbiology Peking University Health Science Center Beijing China Department of Microbiology and Infectious Diseases University of Calgary Calgary Canada 

出 版 物：《Science China(Life Sciences)》 (中国科学（生命科学英文版）)

年 卷 期：2008年第51卷第2期

页      面：182-189页

核心收录：

学科分类：0710[理学-生物学] 1007[医学-药学(可授医学、理学学位)] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 100705[医学-微生物与生化药学] 07[理学] 071005[理学-微生物学] 10[医学] 

基　　金：the National Natural Science Foundation of China (Grant No. 30370774) the 985 Project of Peking University Health Science Center the Discovery Grant from Natural Sciences and Engineering Research Council of Canada (Grant No. 216912-00) 

主　　题：Z curve Mycoplasma genome balance ori and ter evolution 

摘      要：Mycoplasma are wall-less bacteria with small genomes, which are thought to have resulted from massive genome reductive processes, during which the ori-ter balance may be disrupted. For technical difficulties, ori and ter have been located only in a few Mycoplasma strains. Using the Z curve method, we were able to locate turning points on the Mycoplasma genomes, with the minimum and maximum points co-locating with ori or ter in the reference genomes. Assuming Z curve correctly located ori and ter, we calculated the distances from ori to ter in both directions on the circular genome and calculated the ori-ter balance status. The Mycoplasma genomes were not balanced, possibly as a result of close association of Mycoplasma with hosts, where there would be no other microbes for Mycoplasma to compete with for nutrients, so fastest possible growth related to balanced genomes might not be needed by Mycoplasma, leading to a relaxing ori-ter balance.