aminoacyltransferases

Aminoacyltransferases are a class of enzymes that play a crucial role in protein synthesis, specifically in the process of translation. These enzymes are responsible for attaching specific amino acids to their corresponding transfer RNA (tRNA) molecules, a process known as aminoacylation. This reaction occurs in two steps: first, the amino acid is activated by an aminoacyl-adenylate intermediate, and then it is transferred to the 3'-end of the tRNA. The aminoacyl-tRNA complex is then ready to be incorporated into the growing polypeptide chain during translation.

Aminoacyltransferases are highly specific, each enzyme catalyzing the attachment of a particular amino acid to its cognate tRNA. This specificity is crucial for ensuring the correct sequence of amino acids in the final protein product. The enzymes are typically named after the amino acid they activate, for example, aspartyl-tRNA synthetase for aspartic acid.

These enzymes are essential for cellular function and are often targets for antibiotics. For instance, streptomycin and erythromycin inhibit prokaryotic aminoacyltransferases, disrupting protein synthesis and leading to bacterial cell death. In eukaryotes, aminoacyltransferases are also vital, but they are not typically targeted by antibiotics due to differences in their structure and function compared to their prokaryotic counterparts.