Linked Life Data

17960247

Source:http://linkedlifedata.com/resource/pubmed/id/17960247

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7165
pubmed:dateCreated
2007-10-25
pubmed:abstractText
Large-scale domain rearrangements in proteins have long been recognized to have a critical function in ligand binding and recognition, catalysis and regulation. Crystal structures have provided a static picture of the apo (usually open) and holo usually closed) states. The general question arises as to whether the apo state exists as a single species in which the closed state is energetically inaccessible and interdomain rearrangement is induced by ligand or substrate binding, or whether the predominantly open form already coexists in rapid equilibrium with a minor closed species. The maltose-binding protein (MBP), a member of the bacterial periplasmic binding protein family, provides a model system for investigating this problem because it has been the subject of extensive studies by crystallography, NMR and other biophysical techniques. Here we show that although paramagnetic relaxation enhancement (PRE) data for the sugar-bound form are consistent with the crystal structure of holo MBP, the PRE data for the apo state are indicative of a rapidly exchanging mixture (ns to mus regime) of a predominantly ( approximately 95%) open form (represented by the apo crystal structure) and a minor (approximately 5%) partially closed species. Using ensemble simulated annealing refinement against the PRE data we are able to determine a <r(-6)> ensemble average structure of the minor apo species and show that it is distinct from the sugar-bound state.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1476-4687
pubmed:author
pubmed:issnType
Electronic
pubmed:day
25
pubmed:volume
449
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1078-82
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Open-to-closed transition in apo maltose-binding protein observed by paramagnetic NMR.
pubmed:affiliation
Laboratory of Chemical Physics, Building 5, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, USA.
pubmed:publicationType
Journal Article