Linked Life Data

8810927

Source:http://linkedlifedata.com/resource/pubmed/id/8810927

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
37
pubmed:dateCreated
1996-10-29
pubmed:abstractText
Electron paramagnetic resonance spectroscopy at 139.5 GHz has been used to study p21 ras complexed with Mn(II) and guanosine 5'-(beta, gamma-imidotriphosphate), an analog of GTP. The p21 sample studied was selectively labeled with [17O gamma]threonine to a final enrichment of 30%. A Mn(II)-17O hyperfine interaction was observed, but the value of the coupling constant, 0.11 +/- 0.04 mT, is the smallest such value yet reported. Ab initio calculations indicate that this value is consistent with direct coordination of the threonine hydroxyl group and provide an estimate for the Mn(II)-17O bond length of 2.7 A. The measured hyperfine coupling constant and associated bond length starkly contrast with typical values for Mn(II)-17O coordination complexes, namely, approximately 0.25 mT and approximately 2.2 A, respectively. This contrast underscores the peculiar weakness of this Mn(II)-O interaction in p21 and persuasively argues that the nucleotide-induced conformational change, which is known to encompass the region of p21 involving Thr35, is not driven by Mn(II) coordination of the Thr35 hydroxyl group.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
17
pubmed:volume
35
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
12194-2200
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
High frequency (139.5 GHz) electron paramagnetic resonance spectroscopy of the GTP form of p21 ras with selective 17O labeling of threonine.
pubmed:affiliation
Department of Biochemistry, Brandeis University, Waltham, Massachusetts 02154, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.