STRUCTURE AND DYNAMICS OF ESCHERICHIA-COLI CHEMOSENSORY RECEPTORS - ENGINEERED SULFHYDRYL STUDIES
STRUCTURE AND DYNAMICS OF ESCHERICHIA-COLI CHEMOSENSORY RECEPTORS - ENGINEERED SULFHYDRYL STUDIES
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DOI：
10.1016/s0006-3495(92)81806-4
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发表时间：
1992-04-01
影响因子：
3.4
通讯作者：
FALKE, JJ
中科院分区：
文献类型：
--
作者：
CAREAGA, CL;FALKE, JJ
通过定点突变引入半胱氨酸残基，研究了大肠杆菌中两种受体的构象和动力学。大肠杆菌趋化途径。(a)研究了周质D-半乳糖和D-葡萄糖受体（一种已知结构的球状蛋白）中多肽骨架的热运动。在表面α-螺旋I和X的相对运动期间，使用工程巯基对之间的二硫键形成来捕获碰撞。 分别在10（-4）到10（-1）s的时间尺度上检测到幅度为4.5到15.2埃的运动。这些结果表明，热骨干运动可能有更大的振幅比以前认为的。(b)跨膜天冬氨酸转换器的构象特征已被研究。工程巯基被用来确定两个推定的跨膜α-螺旋在一级结构中的位置和方向，研究这些螺旋的包装，以确定低聚物和表面结构，并检测多肽骨架的热和配体诱导的动力学。一个模型的转换器低聚物的折叠构象进行审查。
Cysteine residues introduced by site-directed mutagenesis have been used to probe the conformation and dynamics of two receptors in the E. coli chemotaxis pathway. (a) Thermal motions of the Polypeptide backbone were investigated in the periplasmic D-galactose and D-glucose receptor, a globular protein of known structure. Disulfide bond formation between pairs of engineered sulfhydryls were used to trap collisions during the relative motions of surface alpha-helices I and X. Motions with amplitudes ranging from 4.5 to 15.2 angstrom were detected on timescales ranging from 10(-4) to 10(-1) s, respectively. These results suggest that thermal backbone motions may have larger amplitudes than previously thought. (b) Conformational features of the transmembrane aspartate transducer have been investigated. Engineered sulfhydryls were used to ascertain the location and orientations of two putative transmembrane alpha-helices in the primary structure, to investigate the packing of these helices, to determine the oligomer and surface structures, and to detect thermal and ligand-induced dynamics of the polypeptide backbone. A model for the folded conformation of the transducer oligomer is reviewed.