文章基本信息

标题：Membrane channel structure of Helicobacter pylori vacuolating toxin: Role of multiple GXXXG motifs in cylindrical channels
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作者：Sanguk Kim ; Aaron K. Chamberlain ; James U. Bowie 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2004
卷号：101
期号：16
页码：5988-5991
DOI：10.1073/pnas.0308694101
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Helicobacter pylori is a human pathogen responsible for severe gastric diseases such as peptic ulcers, gastric adenocarcinoma, and gastric lymphoma. Vacuolating toxin (VacA) is crucial in facilitating the colonization of the gastric lining by inducing cell apoptosis and immune suppression. VacA inserts into membranes and forms a hexameric, anion-selective pore. Here we present a structural model of the VacA pore that strongly resembles the structure of an unrelated anion-selective channel, MscS. In our model, Gly residues in GXXXG motifs pack against small Ala or Val side chains to generate the pore. Our model suggests that the same design of two anion-selective channels was achieved by two different evolutionary paths and provides insight into the mechanism of VacA function.
关键词：MscS ; membrane protein ; structure prediction ; anion channel