Blechschmidt B, Shirokov V, Sprinzl M
Laboratorium für Biochemie, Universität Bayreuth, Germany.
Eur J Biochem. 1994 Jan 15;219(1-2):65-71. doi: 10.1111/j.1432-1033.1994.tb19915.x.
An undecagold cluster (Au11) of molecular mass 6200Da was attached to the 3-(3-amino-3-carboxypropyl)uridine at position 47 of tRNA(Phe) from Escherichia coli. This modified tRNA can be enzymically aminoacylated with phenylalanine in the reaction catalyzed by phenylalanyl-tRNA synthetase. Au11-labeled Phe-tRNA(Phe) forms a ternary complex with the elongation factor Tu.GTP and is active in poly(U)-dependent poly(phe) synthesis. The Au11 modification does not hinder the specific binding of tRNA to distinct ribosomal binding sites or the precise positioning of the aminoacyl and peptidyl residues in the peptidyltransferase center, and does not impair the translocation. The modified tRNA is suitable for the identification of ribosomal binding sites by scanning transmission electron microscopy and for crystallographic studies of the 70S ribosome at different states of the protein-elongation cycle.
一个分子量为6200道尔顿的十一金簇（Au11）连接到来自大肠杆菌的tRNA（Phe）第47位的3-（3-氨基-3-羧丙基）尿苷上。这种修饰的tRNA在苯丙氨酰-tRNA合成酶催化的反应中可以被苯丙氨酸酶促氨酰化。Au11标记的Phe-tRNA（Phe）与延伸因子Tu.GTP形成三元复合物，并在依赖于聚（U）的聚（苯丙氨酸）合成中具有活性。Au11修饰并不妨碍tRNA与不同核糖体结合位点的特异性结合，也不妨碍氨酰基和肽基残基在肽基转移酶中心的精确定位，并且不损害转位。修饰后的tRNA适用于通过扫描透射电子显微镜鉴定核糖体结合位点，以及用于对处于蛋白质延伸循环不同状态的70S核糖体进行晶体学研究。
