engleski

Evolution of determinants in seryl-tRNA synthesis

The availability of many genomic sequences obtained in the course of genome sequencing projects, enabled us to investigate the co- adaptation of serine specific aminoacyl-tRNA synthetases (SerRS) with their cognate tRNAs through evolution. We have cloned and expressed SerRS genes belonging to different taxonomic domains, constructed and purified series of mutated enzymes, and studied their interaction with in vitro transcribed synthetic tRNA genes. Our studies have shown that the accuracy of serylation is enhanced by substrate induced conformational changes of the enzymes. The structure and the flexibility of SerRS motif 2 loop is crucial for the tRNA dependent optimization of serine binding, which may reveal a novel mechanism for maintaining translational fidelity. Since majority of seryl-tRNA synthetases, with exception of those from methanogenic Archaea, have quite conserved motif 2 sequences, these enzymes provide an excellent model system for studying the evolution of substrate recognition, including the conformational polymorphism associated with substrate binding.

seryl-tRNA ; evolution ; aminoacyl-tRNA synthetase

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