Crystallization of Pure Species of Bacterial tRNA for X‐Ray Diffraction Studies

Three pure species of bacterial tRNA have been crystallized by several different methods for X‐ray diffraction studies. Extensive studies of tRNAfMet produced many crystal forms, seven of which are noted here. Crystallization conditions for both tRNATyr and tRNAPhe have been systematically investigated for a limited number of solvents. Several forms of tRNATyr can be produced in a controlled fashion. The most favourable unit cells are P4122, a= 7.1 nm, c= 17.4 nm for tRNATyr and P3112, a= 9.3 nm, c= 7.8 nm, for tRNAphe. Initial X‐ray still photographs of tRNATyr and tRNAPhe show some reflections out to 0.4 nm but precession photographs show a rapid fall off in intensity beyond 0.7 nm.