Sensor modules of the osmoregulatory glycine betaine uptake carrier from Corynebacterium glutamicum: structure and interaction with the transport domain Transport-Domäne

谷氨酸棒杆菌的紧耦合甜菜碱摄取系统BetP将电化学Na+梯度的能量转化为甜菜碱的极高化学梯度。BetP的活性严格依赖于跨质膜的渗透梯度的存在。BetP被证明是β-受体和转运蛋白。转运蛋白是一种具有12个跨膜片段的膜蛋白，包括面向细胞质的突出的N-和C-末端延伸，这是在许多原核和真核生物活性膜蛋白中观察到的特性。这些扩展已被证明涉及传感器功能。N-和C-末端模块将分别以不同的长度表达，BetP的膜嵌入部分也是如此。我们建议使用各种光谱技术，特别是核磁共振光谱学，以及X射线晶体学研究BetP的亲水模块的结构及其与运输域的结构相互作用。

The tightly coupled betaine uptake system BetP of Corynebacterium glutamicum converts the energy of an electrochemical Na+ gradient into an extremely high chemical gradient of betaine. The activity of BetP strictly depends on the presence of an osmotic gradient across the plasma membrane. BetP was shown to be both osmosensor and transporter. The transporter is a membrane protein with 12 transmembrane segments and includes prominent N- and C-terminal extensions facing the cytoplasm, a property observed in many pro- and eukarytic osmoactive membrane proteins. These extensions have been shown to be involved in the sensor function. The N- and C-terminal modules will be separately expressed in different lengths, as well as the membrane-embedded part of BetP. We propose to study the structure of the hydrophilic modules of BetP and its structural interaction with the transport domain by using various spectroscopic techniques, in particular NMR spectroscopy, and also X-ray crystallography.