SOLUTE TRANSPORT TAXIS AND SENSORY PATHWAY RECEPTORS

描述：一些结合蛋白（或 受体）。 而X射线晶体学 将使用的主要实验方法，生物化学，重组 DNA和计算技术也将被采用。 这些蛋白质- 对各种碳水化合物、含氧酸（硫酸盐和 磷酸盐）、氨基酸、二肽和寡肽-作为起始肽。 ATP驱动的转运系统或渗透酶的高亲和力受体， 细菌 这组渗透酶是ATP超家族的成员 结合转运蛋白不仅存在于原核生物中，也存在于真核生物中 (e.g.哺乳动物P-糖蛋白多药耐药基因产物， 囊性纤维化跨膜传导调节因子）。 三 结合蛋白也作为初级化学感受器在简单 趋化性行为反应 建议对所选的配体形式的结构进行改进， 结合蛋白（例如具有磷酸盐，硫酸盐， 阿拉伯糖、麦芽糖结合蛋白、亮氨酸/异亮氨酸/缬氨酸）接近1A 使用SHELXL的分辨率。 由微生物家族识别的各种各样的溶质或营养素 受体和广谱的特异性程度，从最 从严格的（例如磷酸盐）到最松散的（寡肽）是一种 分子识别的详细研究的机会。 特别 感兴趣的是静电和疏水的相对贡献 交互. 计算技术将被探索，以评估其 这些相互作用的相对贡献的预测值， 受体家族中的特异性分子识别范例（磷酸 vs.硫酸盐、单糖与寡糖、肽与氨基酸等）。 受体提供了一个很好的机会，深入研究结构 大小范围为约25至60 kDa的蛋白质家族的特征 并且几乎没有序列同源性，但可能会折叠成类似的 整体立体结构。

DESCRIPTION: The structure and function of a number of binding proteins (or receptors) are to be determined. Whereas, X-ray crystallography is the primary experimental approach which will be used, biochemical, recombinant DNA and computational techniques will also be employed. These proteins - with specificity for a variety of carbohydrates, oxyacids (sulfate and phosphate), amino acids, dipeptides and oligopeptides - serve as initial high affinity receptors of ATP-driven transport systems or permeases in bacteria. This group of permeases is a member of a superfamily of ATP binding transporters found not only in prokaryotes but also in eukaryotes (e.g. the mammalian P-glycoprotein multi-drug resistance gene product and the cystic fibrosis transmembrane conductance regulator). Three of the binding proteins also serve as primary chemoreceptors in the simple behavioral response of chemotaxis. It is proposed to refine the structures of the liganded forms of selected binding proteins (e.g. those with specificity of phosphate, sulfate, arabinose, maltose-binding protein, leucine/isoleucine/valine) close to 1 A resolution using SHELXL. The wide variety of solutes or nutrients recognized by the family of receptors and the wide spectrum in the degree of specificity from the most stringent (e.g. phosphate) to the most loose (oligopeptides) is an opportunity for detailed study of molecular recognition. Of particular interest are the relative contributions of electrostatic and hydrophobic interactions. Computational techniques are to be explored to evaluate their predictive value as to the relative contribution of these interactions to specific molecular recognition paradigms in the receptor family (phosphate vs. sulfate, mono- vs. oligosaccharides, peptides vs. amino acids, etc.). The receptors offer an excellent opportunity to delve into structural features of a family of proteins which range in size from about 25 to 60 kDa and share little sequence homology, yet presumably fold into a similar overall three-dimensional structure.