SIDECHAIN ASSIGNMENT & SOLUTION STRUCT OF GLUTAMINE BINDING PROTEIN

革兰氏阴性杆菌的周质转运系统 负责运输各种物质，例如 糖、氨基酸、多肽、阴离子和其他营养物质 胞质膜。细菌运输系统由以下几部分组成 一种配体特异性结合蛋白和一种膜结合蛋白 很复杂。结合蛋白位于周质间隙， 并充当特定配体的受体。谷氨酰胺渗透酶 该系统为核磁共振研究提供了一个很好的模型 周质结合蛋白依赖膜的研究进展 运输。该系统的结合蛋白-谷氨酰胺结合 蛋白质(GlnBP)，是一种由226个氨基酸组成的单体碱性蛋白质 残基，分子量为24,935道尔顿。它捆绑了 在中性条件下，L-谷氨酰胺的摩尔比为1：1。为了 了解GlnBP对其配体的高度特异性和亲和力 以及配体识别和结合的详细机制， GlnBP-Gln络合物的溶液结构是必要的。我们一直在 GlnBP和Have的主链核磁共振归属研究 分配了大约95%的残留物。现在我们将开始研究 侧链分配和结构确定。H(CCO)NH和4D NOESY实验有望为此目的而进行。

Periplasmic transport systems of Gram-negative bacterial are responsible for transporting a wide variety of substances, such as sugars, amino acids, peptides, anions, and other nutrients, across the cytoplasmic membrane. The bacterial transport systems are composed of a ligand-specific binding protein and a membrane-bound protein complex. The binding proteins are located in the periplasmic space, and act as receptors for a specific ligand. The glutamine permease system provides a good model for the NMR study of the essential processes of the periplasmic binding protein-dependent membrane transport. The binding protein of the system, glutamine-binding protein (GlnBP), is a monomeric basic protein, with 226 amino-acid residues and a molecular weight of 24,935 Daltons. It binds L-glutamine with a molar ratio of 1:1 at neutral pH. In order to understand the high specificity and affinity of GlnBP for its ligand as well as the detailed mechanisms of ligand recognition and binding, a solution structure of GlnBP-Gln complex is necessary. We have been working on the backbone NMR resonance assignments of GlnBP and have assigned about 95% of the residues. Now we will start working on the sidechain assignments and structure determination. H(CCO)NH and 4D NOESY experiment are expected to be run for this purpose.