Anomalous Dispersion with Edges in the Soft X-ray Region: First Results of Diffraction from Single Crystals of Ribosomes Near the K-Absorption Edge of Phosphorus

Abstract

X-ray diffraction from a single crystal of the small ribosomal subunit of Thermus thermophilus was measured at five wavelengths near the K-absorption edge of phosphorus. The intensity of the low-order diffraction peaks varies strongly with the wavelength. It is influenced by the dispersion of contrast due to the P atoms of the ribosomal ribonucleic acid and by that of absorption, in comparable amounts.