首页    期刊浏览 2024年12月05日 星期四
登录注册

文章基本信息

  • 标题:Structure, function, and ion-binding properties of a K+ channel stabilized in the 2,4-ion–bound configuration
  • 本地全文:下载
  • 作者:Cholpon Tilegenova ; Cholpon Tilegenova ; D. Marien Cortes
  • 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:2019
  • 卷号:116
  • 期号:34
  • 页码:16829-16834
  • DOI:10.1073/pnas.1901888116
  • 出版社:The National Academy of Sciences of the United States of America
  • 摘要:Here, we present the atomic resolution crystallographic structure, the function, and the ion-binding properties of the KcsA mutants, G77A and G77C, that stabilize the 2,4-ion–bound configuration (i.e., water, K+, water, K+-ion–bound configuration) of the K+ channel’s selectivity filter. A full functional and thermodynamic characterization of the G77A mutant revealed wild-type–like ion selectivity and apparent K+-binding affinity, in addition to showing a lack of C-type inactivation gating and a marked reduction in its single-channel conductance. These structures validate, from a structural point of view, the notion that 2 isoenergetic ion-bound configurations coexist within a K+ channel’s selectivity filter, which fully agrees with the water–K+-ion–coupled transport detected by streaming potential measurements.
  • 关键词:ion permeation ; KcsA ; ion selectivity ; potassium channels ; selectivity filter
国家哲学社会科学文献中心版权所有