Cover illustration

January 18, 2000; 97 (2)
Cover image expansion

Cover image: X-ray radiation from a synchrotron source can rapidly damage a protein crystal and impede data interpretation. The nine images illustrate a time course of electron density maps from the same protein crystal. Protein degradation is indicated by the disappearance of the disulfide bond (empty blue cage) linking the carbon chains (white balls). See article by Weik et al. on pages 623–628 in this issue.