Masaru Tateno

A three-dimensional structure model of the complex of glutamyl-tRNA synthetase and its cognate tRNA

A docking model of glutamyl‐tRNA synthetase (GluRS) and tRNAGlu was constructed, on the basis of the distinguished similarity between the X‐ray crystallographic three‐dimensional structures of the N‐terminal halves of the Thermus thermophilus GluRS in the free state and the Escherichia coli glutaminyl‐tRNA synthetase in a complex with tRNAGln. The modeled structure is energetically favorable and is also well consistent with the results of site‐directed mutagenesis studies. The model indicates that the GluRS‐specific insertions 2 and 3 fit and bind to the acceptor stem and the D arm, respectively, of the cognate tRNA without affecting other contacts. In particular, insertion 3 strongly interacts with the two D‐stem base pairs that are essential for the tRNA·GluRS recognition.

Functional Structures of Class-I Aminoacyl-tRNA Synthetases

Aminoacyl-tRNA synthetase (aaRS) catalyzes the two-step aminoacylation reaction: the amino acid and the ATP form an aminoacyl-AMP in the first step, and the aminoacyl moiety is transferred to the 3’ adenosine of the tRNA in the second step.