Novel method for the rapid evaluation of packing in protein structures.
There has been considerable effort to predict the structure of proteins from their amino acid sequences. A major problem in all prediction efforts has been that, short of a direct comparison with crystallographic co-ordinates, it is often difficult to evaluate the merit of a model, or "proposed" protein structure. Here, we present a method for evaluating proposed protein structures that does not require a structural model of complete atomic detail. Our method evaluates residue-residue packing density using a simplified model of the polypeptide chain where amino acids are represented as one, two (histidine, tyrosine and phenylalanine), or three (tryptophan) spheres. This method also gives a measure of the appropriateness of residue-residue contacts, thus giving a measure of the amino acid distribution throughout the protein. Amino acid packing and amino acid distribution, as evaluated by this technique, are consistent with the accuracy of model-built structures. We have been able to select the best structures from a set of combinatorially generated models using this method, and we anticipate that it will be useful as a general tool for model-building.
Gregoret
L M
LM
Department of Pharmaceutical Chemistry, University of California, San Francisco 94143-0446.
Cohen
F E
FE
D000595:Amino Acid Sequence; D000596:Amino Acids; D008958:Models, Molecular; D011487:Protein Conformation; D011506:Proteins
D000596:Amino Acids; D011506:Proteins