Validating the use of database potentials in protein structure determination by NMR.

The refinement of protein structures determined by nuclear magnetic resonance spectroscopy against database potentials of mean force allows for the exclusion of unfavourable conformations of the protein backbone during a structure calculation, resulting in protein structures with a marked improvement in Ramachandran statistics. In this communication, we use multiple sets of residual dipolar couplings as quality assessment criteria for several proteins and show that not only do the Ramachandran and structural quality statistics improve, but a significant improvement in the accuracy of structures is achieved upon refinement.