Linked Life Data

1854440

Source:http://linkedlifedata.com/resource/pubmed/id/1854440

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1991-8-28
pubmed:abstractText
An efficient algorithm for the determination of an everywhere positive electron-density distribution that agrees with observed structure amplitudes has been used to determine the phases of X-ray diffraction data from recombinant bovine chymosin, a protein with 323 amino-acid residues in the molecular chain whose structure was recently determined using molecular replacement methods. A systematic procedure for testing the signs of centric reflections, using the total entropy of the map as a figure of merit, was used to produce a low-resolution map. The phases of acentric and additional centric reflections were then chosen by adding them to the map with various possible phases and computing the total entropy of the resulting map. Of 159 centric reflections whose phases were chosen by this procedure, 141 had the same phase as in the refined structure. The median absolute phase difference for 1811 acentric reflections was 32 degrees. A map produced from these 1970 reflections, out of 12,346 reflections in the data set, showed a remarkable agreement with the refined structure. This molecule is many times larger than any whose structures have previously been determined without the use of isomorphous replacement, molecular replacement or anomalous dispersion, and the map demonstrates the potential of maximum-entropy methods in macromolecular structure determination.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0108-7673
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
47 ( Pt 3)
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
216-23
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Ab initio phase determination for X-ray diffraction data from crystals of a native protein.
pubmed:affiliation
Institute for Inorganic Chemistry, Chalmers University of Technology, Göteborg, Sweden.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't