DAUNORUBICIN DPSH GENE:STARTER UNIT & CYCLIZ PATTERN:TYPE II POLYKETIDE SYNTHASE

革兰氏阴性菌的周质转运系统是 负责运输各种物质，例如 糖、氨基酸、肽、阴离子和其他营养素， 细胞质膜 细菌转运系统由以下组成： 配体特异性结合蛋白和膜结合蛋白 复杂. 结合蛋白位于周质空间， 并作为特定配体的受体。 谷氨酰胺通透酶 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突起 运输 该系统的结合蛋白，谷氨酰胺结合 GlnBP是一种由226个氨基酸组成的碱性蛋白质 残基和24，935道尔顿的分子量。 其结合 L-谷氨酰胺，在中性pH下摩尔比为1：1。 了解GlnBP对其配体的高特异性和亲和力 以及配体识别和结合的详细机制， GlnBP-Gln复合物的溶液结构是必需的。 我们一直 研究GlnBP的骨架NMR共振归属， 分配了大约95%的残基。 现在我们开始研究 侧链分配和结构确定。 H（CCO）NH和4D NOESY实验预计将为此目的运行。

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.