RECOGNITION OF A TRANSFER RNA WITH A LONG EXTRA ARM

本提案的目的是阐明硫杆菌如何 氧化亚铁酪氨酰-tRNA合成酶特异性识别其同源物 转移RNA，一种具有长的额外臂的tRNA，并歧视非转移RNA。 同源转移RNA。通过制造突变的tRNA基因和酪氨酰-tRNA 合成酶变体，我们提出定义在合成酶中的元件的身份。 转移RNA负责酶的准确识别。在 此外，在体外产生的突变体的酶应该阐明 对于结合底物ATP重要的氨基酸残基， 酪氨酸和转移RNA。T.氧化亚铁酶基因 编码酪氨酰-tRNA合成酶的基因，并寻找其第二个基因， 酶也将被使用。 这些研究将补充和扩展我们正在进行的tRNA项目 以E. coli1.5-氨基酰-tRNA合成酶系统。

The objective of this proposal is to elucidate how Thiobacillus ferrooxidans tyrosyl-tRNA synthetase specifically recognizes its cognate transfer RNA, a tRNA with a long extra arm, and discriminates against non- cognate transfer RNAs. By making mutant tRNA genes and tyrosyl-tRNA synthetase variants we propose to define the identity of elements in the transfer RNA responsible for the accurate recognition by the enzyme. In addition, in vitro generated mutants of the enzyme should shed light on the amino acid residues important for binding the substrates ATP, tyrosine, and transfer RNA. The expression of the T. ferrooxidans gene encoding tyrosyl-tRNA synthetase and the search for a second gene for this enzyme will also be undertaken. These studies will complement and extend our ongoing project on tRNA recognition centering on the E. coli glutaminyl-tRNA synthetase system.