X-ray diffraction analysis of a human tRNAGly acceptor-stem microhelix isoacceptor at 1.18 Å resolution

Interest has been focused on comparative X-ray structure analyses of different tRNA^Gly acceptor-stem helices. tRNA^Gly/glycyl- tRNA synthetase belongs to the so-called class II system, in which the tRNA identity elements consist of simple and unique determinants that are located in the tRNA acceptor stem and the discriminator base. Comparative structure investigations of tRNA^Gly microhelices provide insight into the role of tRNA identity elements. Predominant differences in the structures of glycyl-tRNA synthetases and in the tRNA identity elements between prokaryotes and eukaryotes point to divergence during the evolutionary process. Here, the crystallization and high-resolution X-ray diffraction analysis of a human tRNA^Gly acceptor-stem microhelix with sequence 5′-G ₁C₂A₃U₄U₅G ₆G₇-3′, 5′-C₆₆C₆₇A ₆₈A₆₉U₇₀G₇₁C₇₂-3′ is reported. The crystals belonged to the monoclinic space group C2, with unit-cell parameters a = 37.32, b = 37.61, c = 30.47 Å, β = 112.60° and one molecule per asymmetric unit. A data set was collected using synchrotron radiation and data were processed within the resolution range 50.0-1.18 Å. The structure was solved by molecular replacement.