Generation and evaluation of a large mutational library from the Escherichia coli mechanosensitive channel of large conductance, MscL -: Implications for channel gating and evolutionary design
Generation and evaluation of a large mutational library from the Escherichia coli mechanosensitive channel of large conductance, MscL -: Implications for channel gating and evolutionary design
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DOI：
10.1074/jbc.m302892200
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发表时间：
2003-06-06
影响因子：
4.8
通讯作者：
Dougherty, DA
中科院分区：
文献类型：
--
作者：
Maurer, JA;Dougherty, DA
随机诱变的机械敏感通道的大电导（MscL）从大肠杆菌加上高通量功能筛选通道的结构和功能提供了新的见解。互补相互作用的保守残基提出的门控计算模型进行了评估，并已确定的通道的重要功能区域。突变分析表明，建议的S1螺旋，尽管有几个高度保守的残基，可以严重突变，而不显着改变通道功能。使MscL更难以门控的突变模式表明，MscL与位于双层的脂质头基附近的残基感测张力。所看到的表型变化的范围具有影响力的机械敏感通道的进化起源的拟议模型。
Random mutagenesis of the mechanosensitive channel of large conductance ( MscL) from Escherichia coli coupled with a high-throughput functional screen has provided new insights into channel structure and function. Complementary interactions of conserved residues proposed in a computational model for gating have been evaluated, and important functional regions of the channel have been identified. Mutational analysis shows that the proposed S1 helix, despite having several highly conserved residues, can be heavily mutated without significantly altering channel function. The pattern of mutations that make MscL more difficult to gate suggests that MscL senses tension with residues located near the lipid headgroups of the bilayer. The range of phenotypical changes seen has implications for a proposed model for the evolutionary origin of mechanosensitive channels.