Linked Life Data

21707111

Source:http://linkedlifedata.com/resource/pubmed/id/21707111

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
29
pubmed:dateCreated
2011-7-19
pubmed:abstractText
Protein allostery is based on the existence of multiple conformations in equilibrium linked to distinct functional properties. Although evidence of allosteric transitions is relatively easy to identify by functional studies, structural detection of a pre-existing equilibrium between alternative conformations remains challenging even for textbook examples of allosteric proteins. Kinetic studies show that the trypsin-like protease thrombin exists in equilibrium between two conformations where the active site is either collapsed (E*) or accessible to substrate (E). However, structural demonstration that the two conformations exist in the same enzyme construct free of ligands has remained elusive. Here we report the crystal structure of the thrombin mutant N143P in the E form, which complements the recently reported structure in the E* form, and both the E and E* forms of the thrombin mutant Y225P. The side chain of W215 moves 10.9 Å between the two forms, causing a displacement of 6.6 Å of the entire 215-217 segment into the active site that in turn opens or closes access to the primary specificity pocket. Rapid kinetic measurements of p-aminobenzamidine binding to the active site confirm the existence of the E*-E equilibrium in solution for wild-type and the mutants N143P and Y225P. These findings provide unequivocal proof of the allosteric nature of thrombin and lend strong support to the recent proposal that the E*-E equilibrium is a key property of the trypsin fold.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
1520-4995
pubmed:author
pubmed:copyrightInfo
© 2011 American Chemical Society
pubmed:issnType
Electronic
pubmed:day
26
pubmed:volume
50
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6301-7
pubmed:dateRevised
2011-11-14
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Crystallographic and kinetic evidence of allostery in a trypsin-like protease.
pubmed:affiliation
Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, Missouri 63104, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural