Lead Ion Binding and RNA Chain Hydrolysis in Phenylalanine tRNA

Crystalline complexes of yeast phenylalanine tRNA and Lead (II) ion were prepared by soaking pregrown orthorhombic crystals of tRNA in saturated lead chloride solutions. The locations of tightly bound lead ions on the tRNA were determined by difference Fourier methods. There are three major lead binding sites; two of these replace tightly bound magnesium ions in the native tRNA structure. Site I is located in the dihydrouridine loop of the...