Crystallization and X-ray diffraction data of a tRNASec acceptor-stem helix.

tRNASec is a UGA suppressor tRNA which co-translationally inserts selenocysteine into proteins. Its eight-base-pair tRNASec acceptor stem, which contains key recognition elements, was synthesized using solid-phase phosphoramidite RNA chemistry. High-resolution X-ray diffraction data were collected using synchrotron radiation under cryogenic cooling conditions. The crystals diffract to a maximal resolution of 1.8 A. X-ray diffraction data were processed to 2.4 A. tRNASec microhelix crystallizes in space group R32, with cell constants a = 47.02, b = 47.02, c = 373.03 A, alpha = beta = 90, gamma = 120 degrees. The crystals contain three RNA molecules per asymmetric unit.