Functional Monomerization of a ClC-Type Fluoride Transporter.
Functional Monomerization of a ClC-Type Fluoride Transporter.
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DOI：
10.1016/j.jmb.2015.09.027
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发表时间：
2015-11-06
影响因子：
5.6
通讯作者：
Miller C
中科院分区：
文献类型：
--
作者：
Last NB;Miller C
已发现ClC超家族的阴离子通道和反向转运蛋白在性质上仅为二聚体，即使每个单体包含完整的转运途径。在这里，我们描述了通过细菌F−/H+反向转运蛋白ClCF-eca的二聚体界面的诱变的不稳定性。几个突变，产生单体/二聚体平衡的正常二聚体转运蛋白被发现，在某些情况下，简单地通过缩短疏水侧链。一个突变，L376 W，导致显示完全活性的完全单体变体。此外，我们发现了一种天然不稳定的同源物，ClCF-rla，它在洗涤剂中经历部分单体化而没有额外的突变。这些结果，与以前的功能单体化的远亲ClC-ec 1相结合，表明单体单独是几个分支的ClC超家族的功能单元。
Anion channels and antiporters of the ClC superfamily have been found to be exclusively dimeric in nature, even though each individual monomer contains the complete transport pathway. Here, we describe the destabilization through mutagenesis of the dimer interface of a bacterial F−/H+ antiporter, ClCF-eca. Several mutations that produce monomer/dimer equilibrium of the normally dimeric transporter were found, simply by shortening a hydrophobic side chain in some cases. One mutation, L376W, leads to a wholly monomeric variant that shows full activity. Furthermore, we discovered a naturally destabilized homologue, ClCF-rla, which undergoes partial monomerization in detergent without additional mutations. These results, in combination with the previous functional monomerization of the distant relative ClC-ec1, demonstrate that the monomer alone is the functional unit for several clades of the ClC superfamily.