Structural analysis of prokaryotic and eukaryotic 5S rRNAs by RNase H

Crystallization and preliminary diffraction studies of 5 S rRNA from the thermophilic bacterium Thermus flavus

Crystals of purified 5 S rRNA from Thermus flavus have been obtained. The crystals diffract up to 8 A resolution, using synchrotron radiation, and have the monoclinic space-group C2. The unit cell has the dimensions a = 190 A, b = 110 A, c = 138 A and beta = 117 degrees. The cell volume suggests the presence of four 5 S rRNA molecules per asymmetric unit.

Structural analysis of plant ribosomal 5S RNAs. Visualisation of novel tertiary interactions by cleavage of lupin and wheat 5SrRNAs with ribonuclease H

A model for the tertiary structure of plant 5S rRNA, previously proposed by our laboratory (Joachimiak, A. et al. (1990) Int. J. Biol. Macromol., in press) was tested by specific cleavage of the plant 5S rRNA in the presence of synthetic oligodeoxynucleotides. The hexanucleotides used in this study were complementary to different portions of loops C, D and E, the nucleotides of which have recently been proposed to be involved in tertiary hydrogen bonds. The results obtained strongly support the interaction of loops C and D by nucleotides C34, C35, C36, A37 and G85, G86, G87, U88, respectively. Digestion pattern of loop E (domain gamma, nucleotides 66-110) suggests a possible different arrangement of this part of the plant 5S rRNA molecule, when compared with other eukaryotes.