Linked Life Data

17397188

Source:http://linkedlifedata.com/resource/pubmed/id/17397188

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
17
pubmed:dateCreated
2007-4-24
pubmed:abstractText
Elongation factor Tu (EF-Tu) belongs to the family of GTP-binding proteins and requires elongation factor Ts (EF-Ts) for nucleotide exchange. Crystal structures suggested that one of the salient features in the EF-Tu x EF-Ts complex is a conformation change in the switch II region of EF-Tu that is initiated by intrusion of Phe81 of EF-Ts between His84 and His118 of EF-Tu and may result in a destabilization of Mg2+ coordination and guanine nucleotide release. In the present paper, the contribution of His84 to nucleotide release was studied by pre-steady-state kinetic analysis of nucleotide exchange in mutant EF-Tu in which His84 was replaced by Ala. Both intrinsic and EF-Ts-catalyzed nucleotide release was affected by the mutation, resulting in a 10-fold faster spontaneous GDP release and a 4-fold faster EF-Ts-catalyzed release of GTP and GDP. Removal of Mg2+ from the EF-Tu x EF-Ts complex increased the rate constant of GDP release 2-fold, suggesting a small contribution to nucleotide exchange. Together with published data on the effects of mutations interfering with other putative interactions between EF-Tu and EF-Ts, the results suggest that each of the contacts in the EF-Tu x EF-Ts complex alone contributes moderately to nucleotide destabilization, but together they act synergistically to bring about the overall 60,000-fold acceleration of nucleotide exchange in EF-Tu by EF-Ts.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
46
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4977-84
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Mechanism of EF-Ts-catalyzed guanine nucleotide exchange in EF-Tu: contribution of interactions mediated by helix B of EF-Tu.
pubmed:affiliation
Institute of Physical Biochemistry, University of Witten/Herdecke, D-58448 Witten, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't