Open AccessAmino acid modifications on tRNA †
Author(s) -
Yuan Jing,
Sheppard Kelly,
Söll Dieter
Publication year - 2008
Publication title -
acta biochimica et biophysica sinica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.771
H-Index - 57
eISSN - 1745-7270
pISSN - 1672-9145
DOI - 10.1111/j.1745-7270.2008.00435.x
Subject(s) - transfer rna , amino acid , amino acyl trna synthetases , aminoacyl trna synthetase , enzyme , biochemistry , translation (biology) , chemistry , biology , rna , stereochemistry , messenger rna , gene
The accurate formation of cognate aminoacyl‐transfer RNAs (aa‐tRNAs) is essential for the fidelity of translation. Most amino acids are esterified onto their cognate tRNA isoacceptors directly by aa‐tRNA synthetases. However, in the case of four amino acids (Gln, Asn, Cys and Sec), aminoacyl‐tRNAs are made through indirect pathways in many organisms across all three domains of life. The process begins with the charging of noncognate amino acids to tRNAs by a specialized synthetase in the case of Cys‐tRNA Cys formation or by synthetases with relaxed specificity, such as the non‐di scr iminating glutamyl‐tRNA, non‐disc rimi nati ng aspartyl‐tRNA and seryl‐tRNA synthetases. The resulting misacylated tRNAs are then converted to cognate pairs through transformation of the amino acids on the tRNA, which is catalyzed by a group of tRNA‐dependent modifying enzymes, such as tRNA‐dependent amidotransferases, Sep‐tRNA:Cys‐tRNA synthase, O ‐phosphoseryl‐tRNA kinase and Sep‐tRNA:Sec‐tRNA synthase. The majority of these indirect pathways are widely spread in all domains of life and thought to be part of the evolutionary process.