HAD, a data bank of heavy-atom binding sites in protein crystals: a resource for use in multiple isomorphous replacement and anomalous scattering

Information on the preparation and characterization of heavy-atom derivativ es of protein crystals has been collected, either from the literature or di rectly from protein crystallographers, and assembled in the form of a heavy -atom data bank (HAD). The data bank contains coordinate data for the heavy -atom positions in a form that is compatible with the crystallographic data in the Brookhaven Protein Data Bank, together with a wealth of information on the crystallization conditions, the nature of the heavy-atom reagent an d references to relevant publications. Some statistical information derived from the data bank, such as the most popular heavy-atom derivatives, is al so included. The information can be directly accessed and should be useful to protein crystallographers seeking to improve their success in preparing heavy-atom derivatives for the methods of isomorphous replacement and anoma lous dispersion. The World Wide Web address of HAD is http://www.icnet.uk/b mm/had.