Bestimmung von Strukturelementen der tRNA, die beteiligt sind an der Aminosäure-Erkennung durch Aminoacyl-tRNA Synthetasen

点击翻译按钮获取中文摘要

Accuracy in the transfer of information from gene to protein is essential for viable life forms. The initial step in this process is dependent on the ability of the aminoacyl-tRNA synthetase enzymes to discriminate between amino acids and to attach these to the correct tRNA molecules. Several mechanisms guaranteeing specificity in amino acid selection have been described. Substrate recognition may occur independently for amino acid and tRNA but recent results concerning a sub-family of these enzymes have provided evidence for an involvement of the tRNA molecule itself in the amino acid recognition process. “Identity elements” within the tRNA that bring about the specific interaction with enzyme have been characterized in some (mainly prokaryotic) systems. The “recognition elements”, whose interactions with the enzyme mediate an induced-fit type of alteration in the enzyme active site that ultimately leads to amino acid discrimination, have not yet been defined. Using tRNA mutants and natural variants of arginyltRNA synthetases that distinguish themselves by their ability to discriminate between the allelochemical, canavanine, we propose to elucidate those elements within the tRNA structure that contribute to the fidelity of protein biosynthesis.