...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of bacteriology >Domain Interactions in the Yeast ATP Binding Cassette Transporter Ycf1p: Intragenic Suppressor Analysis of Mutations in the Nucleotide Binding Domains
【24h】

Domain Interactions in the Yeast ATP Binding Cassette Transporter Ycf1p: Intragenic Suppressor Analysis of Mutations in the Nucleotide Binding Domains

机译：酵母ATP结合盒式转运蛋白Ycf1p中的域相互作用：核苷酸结合域中的突变的基因内抑制器分析。

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The yeast cadmium factor (Ycf1p) is a vacuolar ATP binding cassette (ABC) transporter required for heavy metal and drug detoxification. Cluster analysis shows that Ycf1p is strongly related to the human multidrug-associated protein (MRP1) and cystic fibrosis transmembrane conductance regulator and therefore may serve as an excellent model for the study of eukaryotic ABC transporter structure and function. Identifying intramolecular interactions in these transporters may help to elucidate energy transfer mechanisms during transport. To identify regions in Ycf1p that may interact to couple ATPase activity to substrate binding and/or movement across the membrane, we sought intragenic suppressors of ycf1 mutations that affect highly conserved residues presumably involved in ATP binding and/or hydrolysis. Thirteen intragenic second-site suppressors were identified for the D777N mutation which affects the invariant Asp residue in the Walker B motif of the first nucleotide binding domain (NBD1). Two of the suppressor mutations (V543I and F565L) are located in the first transmembrane domain (TMD1), nine (A1003V, A1021T, A1021V, N1027D, Q1107R, G1207D, G1207S, S1212L, and W1225C) are found within TMD2, one (S674L) is in NBD1, and another one (R1415G) is in NBD2, indicating either physical proximity or functional interactions between NBD1 and the other three domains. The original D777N mutant protein exhibits a strong defect in the apparent affinity for ATP and V max of transport. The phenotypic characterization of the suppressor mutants shows that suppression does not result from restoring these alterations but rather from a change in substrate specificity. We discuss the possible involvement of Asp777 in coupling ATPase activity to substrate binding and/or transport across the membrane.
机译：酵母镉因子（Ycf1p）是重金属和药物排毒所需的液泡ATP结合盒（ABC）转运蛋白。聚类分析表明，Ycf1p与人类多药相关蛋白（MRP1）和囊性纤维化跨膜电导调节剂密切相关，因此可作为研究真核ABC转运蛋白结构和功能的极佳模型。识别这些转运蛋白中的分子内相互作用可能有助于阐明转运过程中的能量转移机制。为了鉴定Ycf1p中可能相互作用的区域，这些区域可能相互作用以将ATPase的活性与底物结合和/或穿过膜的运动耦合，我们寻求了 ycf1 突变的基因内抑制子，这些突变影响可能高度保守的残基，可能与ATP结合和/或有关。水解。鉴定了13个基因内第二位抑制子的D777N突变，该突变影响了第一个核苷酸结合域（NBD1）的Walker B基序中的恒定Asp残基。两个抑制突变（V543I和F565L）位于第一个跨膜结构域（TMD1）中，其中九个（A1003V，A1021T，A1021V，N1027D，Q1107R，G1207D，G1207S，S1212L和W1225C）位于TMD2中，一个（S674L ）位于NBD1中，而另一个（R1415G）位于NBD2中，表明NBD1与其他三个域之间存在物理邻近关系或功能相互作用。原始的D777N突变蛋白在与运输的ATP和 V max 的表观亲和力方面表现出很强的缺陷。抑制突变体的表型特征表明抑制不是由恢复这些改变引起的，而是由底物特异性的改变引起的。我们讨论了Asp777可能参与的ATPase活性与底物结合和/或跨膜运输的耦合。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号