Probing the structure of the dimeric KtrB membrane protein

被引:21
作者
Albright, Ronald A. [1 ]
Joh, Kyu [1 ]
Morais-Cabral, Joao H. [1 ]
机构
[1] Yale Univ, Dept Mol Biophys & Biochem, New Haven, CT 06520 USA
关键词
D O I
10.1074/jbc.M704260200
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
The KtrAB ion transporter is a complex of two proteins, KtrB and KtrA. The integral membrane protein KtrB is expected to adopt the structural architecture typified by the pore domain of potassium channels. Here we show that homo-dimerization of KtrB proteins is most likely a general property of this family of transporters. Using cysteine mutants and bifunctional cross-linkers we define regions of the Bacillus subtilis KtrB molecule that are close to the molecular 2-fold axis and to the dimer interface. Fitting of the cross-linking data to a potassium channel-like model suggests structural similarities between potassium channels and KtrB proteins in the extracellular half of the molecule and differences in the cytoplasmic regions.
引用
收藏
页码:35046 / 35055
页数:10
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