FEATURES OF MOTA PROTON CHANNEL STRUCTURE REVEALED BY TRYPTOPHAN-SCANNING MUTAGENESIS
FEATURES OF MOTA PROTON CHANNEL STRUCTURE REVEALED BY TRYPTOPHAN-SCANNING MUTAGENESIS
复制标题
DOI：
10.1073/pnas.92.17.7946
复制
发表时间：
1995-08-15
影响因子：
11.1
通讯作者：
BLAIR, DF
中科院分区：
文献类型：
--
作者：
SHARP, LL;ZHOU, JD;BLAIR, DF
大肠杆菌的 MotA 蛋白是鞭毛马达的一个组成部分，在跨膜质子传导中发挥作用。接下来，我们报告了通过使用基于诱变的方法揭示的 MotA 结构的几个特征。在 MotA 的四个疏水片段内的许多位置引入单个色氨酸残基，并且仅测量对功能的影响。功能根据周期性模式被破坏，该模式意味着跨膜片段是α螺旋并且识别每个螺旋的面向脂质的部分。结果支持了 MotA 结构和机制的假设，其中母体分子形成了大部分质子传导途径。这种方法在 MotA 研究中的成功表明它可用于其他整合膜蛋白的结构功能研究。
The MotA protein of Escherichia coli is a component of the flagellar motors that functions in transmembrane proton conduction. sere, we report several features of MotA structure revealed by use of a mutagenesis-based approach. Single tryptophan residues were introduced at many positions within the four hydrophobic segments of MotA, and the effects on function mere measured. Function was disrupted according to a periodic pattern that implies that the membrane-spanning segments are alpha-helices and that identifies the lipid-facing parts of each helix. The results support a hypothesis for MotA structure and mechanism in which mater molecules form most of the proton-conducting pathway. The success of this approach in studying MotA suggests that it could be useful in structure-function studies of other integral membrane proteins.