LAFIRE: software for automating the refinement process of protein-structure analysis

Manual intervention is usually required in the multiple rounds of refinement of protein crystal structures, including linking and/or extending the fragments of the initial model and rebuilding (fitting) ill-matched residues using computer-graphics software. Such manual modification is both time-consuming and requires a great deal of expertise in crystallography. Consequently, the refinement process becomes the bottleneck for high-throughput structure analysis. A program, Local correlation coefficient-based Automatic FItting for REfinement (LAFIRE), has been developed to achieve manual intervention-free refinement. This program was designed to perform the entire process of protein structural refinement automatically using the refinement programs CNS1.1 (CNS v.1.1) or REFMAC5. The automatic process begins from an initial model, which can be approximate, fragmentary or even only main-chain, and refines it to the final model including water molecules, controlled by monitoring the R(free) factor. More than 30 structures have now been refined successfully in a fully or semi-automatic manner within a few hours or days using LAFIRE.