R_omit profile analysis for molecular replacements

A new procedure for evaluation of molecular replacement has been examined by using an R factor calculated from the probe structure with some omitted parts (R_omit). It has been demonstrated that changes in R_omit from the conventional R factor for the whole structure are sensitive to the local fitness in the omitted region even for large molecules such as proteins. Their profile, plotted against residues, is effective for distinguishing the most probable one from several solutions. In addition, this profile analysis exhibits useful information for model building.