Laberge S, Belair M, Verreault A, Bell A W, Bordeleau L M, Lapointe J
Département de biochimie, Faculté des sciences et de génie, Université Laval, Québec, Canada.
Biochem Cell Biol. 1989 Oct;67(10):674-9. doi: 10.1139/o89-101.
A glutamyl-tRNA synthetase has been purified to homogeneity from Rhizobium meliloti, using reversed-phase chromatography as the last step. Amino acid sequencing of the amino-terminal region of the enzyme indicates that it contains a single polypeptide, whose molecular weight is about 54,000, as judged by SDS-gel electrophoresis. The primary structures of the amino-terminus region and of an internal peptide obtained by cleavage of the enzyme with CNBr have similarities of 58 and 48% with regions of the glutamyl-tRNA synthase of Escherichia coli; these are thought to be involved in the binding of ATP and tRNA, respectively. The small amount of glutamyl-tRNA synthetase present in R. meliloti is consistent with the metabolic regulation of the biosynthesis of many aminoacyl-tRNA synthetases.
利用反相色谱作为最后一步，从苜蓿根瘤菌中纯化出了均一的谷氨酰胺-tRNA合成酶。对该酶氨基末端区域的氨基酸测序表明，它含有一条单一的多肽链，通过SDS-凝胶电泳判断，其分子量约为54,000。该酶氨基末端区域以及用溴化氰裂解酶得到的内部肽段的一级结构，与大肠杆菌谷氨酰胺-tRNA合成酶的区域分别有58%和48%的相似性；这些区域分别被认为参与ATP和tRNA的结合。苜蓿根瘤菌中存在的少量谷氨酰胺-tRNA合成酶与许多氨酰-tRNA合成酶生物合成的代谢调控是一致的。
