GLUTAMINE AMIDOTRANSFERASE STRUCTURE/FUNCTION/REGULATION

结构-功能研究将用来自 粘质沙雷氏菌 将使用组特异性试剂对 酶和鉴定NH3依赖性活性所必需的残基。 大 量的E.大肠杆菌酰胺磷酸核糖基转移酶将从 携带purF重组质粒的菌株。 关键活性部位半胱氨酸 将用6-重氮-5-氧代正亮氨酸和活性位点胰蛋白酶肽标记 将被分离并测序 purF基因的核苷酸序列将 确定，从而允许谷氨酰胺活性位点区域被放置在 序列和与其它谷氨酰胺酰胺转移酶的比较。

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.