The application of the molecular replacement method to thede novodetermination of protein structure

Abstract

The determination of a novel protein structure by X-ray diffraction is seldom straightforward. Three hurdles present themselves (i) the protein must be purified in sufficient quantity to allow crystallization trials, (ii) crystals must be grown to adequate size and must diffract to a resolution that will allow atomic detail to be revealed, and (iii) phases must be determined for the diffracted X-ray beams in order that an initial electron-density map may be calculated.