Yeast transfer RNA: a small-angle x-ray study.

The intensity of x-ray scattering and the radius of gyration were measured for a mixture of yeast transfer RNA's in tenth molar potassium chloride. The experimentally observed radius of gyration eliminates single-stranded, hairpin, singly folded hairpin, triple-stranded, and linked double-hairpin models of tRNA but allows certain folded cloverleaf models. The measured intensities at larger angles, beyond the radius of gyration region, lend some support to the Holley's cloverleaf model, in which three arms are folded up tightly together and the fourth arm is extended in the opposite direction.