GLUTAMINE AMIDOTRANSFERASE STRUCTURE/FUNCTION/REGULATION

结构-功能研究将用邻氨基苯甲酸合成酶从 粘质沙雷氏菌。组特异性试剂将被用来灭活 酶，并确定氨依赖活性所必需的残基。大型 大量的大肠杆菌氨基磷酸核糖转移酶将从 携带PurF重组质粒的菌株。半胱氨酸的重要活性部位 将被标记为6-重氮-5-氧代亮氨酸和活性部位胰蛋白酶多肽 将被分离并测序。PurF基因的核苷酸序列将 从而允许将谷氨酰胺活性部位区域放置在 并与其他谷氨酰胺氨基转移酶进行比较。

Structure-function studies are to be conducted with anthranilate synthase from Serratia marcescens. Group-specific reagents will be used to inactivate the enzyme and identify residues essential for NH3-dependent activity. Large amounts of E. coli amidophosphoribosyl transferase will be purified from a strain carrying a purF recombinant plasmid. The essential active site cystein will be labeled with 6-diazo-5-oxonorleucine, and an active site tryptic peptide will be isolated and sequenced. The nucleotide sequence of the purF gene will be determined, thus allowing the glutamine active site region to be placed in the sequence and a comparison with other glutamine amidotransferases to be made.