Identification of type II restriction and modification systems in <i>Helicobacter pylori</i> reveals their substantial diversity among strains

作     者：Xu, Q Morgan, RD Roberts, RJ Blaser, MJ 

作者机构：Vanderbilt Univ Sch Med Dept Microbiol & Immunol Nashville TN 37232 USA Vanderbilt Univ Sch Med Div Infect Dis Nashville TN 37232 USA New England Biolabs Inc Beverly MA 01915 USA 

出 版 物：《PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA》 (美国国家科学院汇刊)

年 卷 期：2000年第97卷第17期

页      面：9671-9676页

核心收录：

学科分类：07[理学] 08[工学] 

基　　金：NIDDK NIH HHS [DK53707] Funding Source: Medline NIGMS NIH HHS [GM56534] Funding Source: Medline 

主　　题：染色体 细菌/遗传学 染色体 细菌/代谢 DNA甲基化 DNA 细菌/化学 DNA 细菌/遗传学 DNA 细菌/代谢 脱氧核糖核酸酶类 位点特异性Ⅱ型/遗传学 脱氧核糖核酸酶类 位点特异性Ⅱ型/分离和提纯 脱氧核糖核酸酶类 位点特异性Ⅱ型/代谢 人种群 遗传变异/遗传学 螺杆菌感染/微生物学 幽门螺杆菌/分类 幽门螺杆菌/酶学 幽门螺杆菌/遗传学 底物特异性 成年人 老年人 女(雌)性 人类 男(雄)性 中年人 

摘      要：A total of 22 type II restriction endonucleases with 18 distinct specificities have been identified in six Helicobacter pylori strains. Among these 18 specificities are three completely new endonucleases, Hpy178III, Hpy991, and Hpy1881, that specifically cleave DNA at TC-NNGA, CCWCG, and TCNGA sites, respectively. The set of endonucleases identified in each strain varies, but ail have four- or five-base recognition sequences. Among 16 H. pylori strains, examination of the DNA modification status at the recognition sites of 15 restriction endonucleases reveals that each main has a substantially different complement of type II modification systems. We conclude that the type tl restriction-modification systems in H. pylori are highly diverse between strains, a unique characteristic of H. pylori. The diverse methylation status of H. pylori chromosomal DNA may serve as a new typing system to discriminate H. pylori isolates for epidemiological and clinical purposes. This study also demonstrates that H, pylori is a rich source of type II restriction endonucleases.