Department of Biochemistry and Molecular Biology, University College, London, England.
Proteins 12: 345-64 (1992)
Abstract
Methods have been developed to assess the stereochemical quality of any
protein structure both globally and locally using various criteria.
Several parameters can be derived from the coordinates of a given
structure. Global parameters include the distribution of phi, psi and
chi 1 torsion angles, and hydrogen bond energies. There are clear
correlations between these parameters and resolution; as the resolution
improves, the distribution of the parameters becomes more clustered.
These features show a broad distribution about ideal values derived from
high-resolution structures. Some structures have tightly clustered
distributions even at relatively low resolutions, while others show
abnormal scatter though the data go to high resolution. Additional
indicators of local irregularity include proline phi angles, peptide
bond planarities, disulfide bond lengths, and their chi 3 torsion
angles. These stereochemical parameters have been used to generate
measures of stereochemical quality which provide a simple guide as to
the reliability of a structure, in addition to the most important
measures, resolution and R-factor. The parameters used in this
evaluation are not novel, and are easily calculated from structure
coordinates. A program suite is currently being developed which will
quickly check a given structure, highlighting unusual stereochemistry
and possible errors.
Mesh Headings
Unique Identifier: 92253561
Chemical Identifiers (Names)