Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2000-11-8
pubmed:abstractText
It is often the case that a substantial number of torsion angles (both backbone and sidechain) in structures of proteins and nucleic acids determined by NMR are found in physically unlikely and energetically unfavorable conformations. We have previously proposed a database-derived potential of mean force comprising one-, two-, three-, and four-dimensional potential surfaces which describe the likelihood of various torsion angle combinations to bias conformational sampling during simulated annealing refinement toward those regions that are populated in very high resolution (< or =1.75 A) crystal structures. We now note a shortcoming of our original implementation of this approach: namely, the forces it places on atoms are very rough. When the density of experimental restraints is low, this roughness can both hinder convergence to commonly populated regions of torsion angle space and reduce overall conformational sampling. In this paper we describe a modification that completely eliminates these problems by replacing the original potential surfaces by a sum of multidimensional Gaussian functions. Structures refined with the new Gaussian implementation now simultaneously enjoy excellent global sampling and excellent local choices of torsion angles.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1090-7807
pubmed:author
pubmed:issnType
Print
pubmed:volume
146
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
249-54
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Sources of and solutions to problems in the refinement of protein NMR structures against torsion angle potentials of mean force.
pubmed:affiliation
Laboratory of Chemical Physics, National Institutes of Health, Building 5, Bethesda, Maryland 20892-0510, USA.
pubmed:publicationType
Journal Article