Yeast aspartyl-tRNA synthetase: a structural view of the aminoacylation reaction.

The refinement of the crystal structure of a binary complex formed by yeast AspRS and tRNA(Asp) provided a detailed understanding of the recognition of tRNA by an aminoacyl-tRNA synthetase. The crystal structures of several complexes containing ATP, alone or with aspartic acid, were also determined and refined. These studies led to a complete description of the active site of the enzyme and to the elucidation of the location and interactions of the various substrates. Based on these structural results, a class II-specific pathway for the aminoacylation reaction can be proposed.