X-ray diffraction patterns of transfer RNA consistent with the presence of short parallel helices in the molecule

X-ray diffraction data of yeast formylmethionine transfer RNA, Escherichia coli phenylalanine transfer RNA, and Escherichia coli arginine transfer RNA single crystals are compared with the Fourier transform of a helix. The results are consistent with the presence of short parallel double helical segments in the transfer RNA molecules.