Linked Life Data

9753553

Source:http://linkedlifedata.com/resource/pubmed/id/9753553

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1998-11-13
pubmed:databankReference
pubmed:abstractText
Crystals of the 61 kDa complex of the cholera toxin B-pentamer with the ganglioside GM1 receptor pentasaccharide diffract to near-atomic resolution. We have refined the crystallographic model for this complex using anisotropic displacement parameters for all atoms to a conventional crystallographic residual R=0.129 for all observed Bragg reflections in the resolution range 22 A to 1.25 A. Remarkably few residues show evidence of discrete conformational disorder. A notable exception is a minority conformation found for the Cys9 side-chain, which implies that the Cys9-Cys86 disulfide linkage is incompletely formed. In all five crystallographically independent instances, the peptide backbone in the region of the receptor-binding site shows evidence of strain, including unusual bond lengths and angles, and a highly non-planar (omega=153.7(7) degrees) peptide group between residues Gln49 and Val50. The location of well-ordered water molecules at the protein surface is notable reproduced among the five crystallographically independent copies of the peptide chain, both at the receptor-binding site and elsewhere. The 5-fold non-crystallographic symmetry of this complex allows an evaluation of the accuracy, reproducibility, and derived error estimates from refinement of large structures at near-atomic resolution. We find that blocked-matrix treatment of parameter covariance underestimates the uncertainty of atomic positions in the final model by approximately 10% relative to estimates based either on full-matrix inversion or on the 5-fold non-crystallographic symmetry.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0022-2836
pubmed:author
pubmed:copyrightInfo
Copyright 1998 Academic Press.
pubmed:issnType
Print
pubmed:day
9
pubmed:volume
282
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1043-59
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
The 1.25 A resolution refinement of the cholera toxin B-pentamer: evidence of peptide backbone strain at the receptor-binding site.
pubmed:affiliation
Department of Biological Structure, Biomolecular Structure Center, University of Washington, Seattle, WA, 98195-7742, USA. merritt@u.washington.edu
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't