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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
6
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pubmed:dateCreated |
1996-2-1
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pubmed:abstractText |
The 'loop' involving residues 98-110 in Bacillus stearothermophilus lactate dehydrogenase (BSLDH) is of great interest as substrate-induced 'loop' closure is thought to be rate-limiting and essential in catalyzing the reaction and in determining substrate specificity. Consequently, we have explored the mechanism underlying 'loop' opening in BSLDH through a molecular dynamics simulation at high temperature (1000 K) in the presence of explicit solvent, starting from the X-ray structure of BSLDH complexed with the co-enzyme NAD+ and oxamate at 2.5 A. During the simulation, a significant conformational change occurred, as evidenced by sharp dihedral angle transitions, hydrogen bond breaking and formation and large root mean square deviations from the starting structure; these changes define the criteria for 'loop' opening. The mechanical elements responsible for 'loop' opening, i.e. 'loop' hinges and flap, are defined through a combination of order parameters, dihedral angle changes and their correlations and the dynamical cross-correlation map of atomic displacements for the 'loop' residues. The results indicate that the 'loop' consists of two flexible hinge regions on either side of a relatively rigid three-residue segment that undergoes a significant spatial displacement during 'loop' opening. 'Loop' opening is made possible through an array of correlated dihedral angle changes and intra-'loop' rearrangements of hydrogen-bond interactions. The present findings are compared to previous work related to 'loop' opening and site-directed mutagenesis experiments.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
|
pubmed:chemical | |
pubmed:status |
MEDLINE
|
pubmed:month |
Jun
|
pubmed:issn |
0269-2139
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pubmed:author | |
pubmed:issnType |
Print
|
pubmed:volume |
8
|
pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
|
pubmed:pagination |
565-73
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pubmed:dateRevised |
2009-11-19
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pubmed:meshHeading |
pubmed-meshheading:8532681-Amino Acid Sequence,
pubmed-meshheading:8532681-Geobacillus stearothermophilus,
pubmed-meshheading:8532681-Hydrogen Bonding,
pubmed-meshheading:8532681-L-Lactate Dehydrogenase,
pubmed-meshheading:8532681-Molecular Sequence Data,
pubmed-meshheading:8532681-Protein Conformation,
pubmed-meshheading:8532681-X-Ray Diffraction
|
pubmed:year |
1995
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pubmed:articleTitle |
Identifying the mechanism of protein loop closure: a molecular dynamics simulation of the Bacillus stearothermophilus LDH loop in solution.
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pubmed:affiliation |
Department of Chemistry, University of Toronto, Ontario, Canada.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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