Linked Life Data

11744709

Source:http://linkedlifedata.com/resource/pubmed/id/11744709

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
2002-2-18
pubmed:abstractText
Nucleotide exchange in elongation factor Tu (EF-Tu) is catalyzed by elongation factor Ts (EF-Ts). Similarly to other GTP-binding proteins, the structural changes in the P loop and the Mg(2+) binding site are known to be important for nucleotide release from EF-Tu. In the present paper, we determine the contribution of the contacts between helix D of EF-Tu at the base side of the nucleotide and the N-terminal domain of EF-Ts to the catalysis. The rate constants of the multistep reaction between Escherichia coli EF-Tu, EF-Ts, and GDP were determined by stopped-flow kinetic analysis monitoring the fluorescence of either Trp-184 in EF-Tu or mant-GDP. Mutational analysis shows that contacts between helix D of EF-Tu and the N-terminal domain of EF-Ts are important for both complex formation and the acceleration of GDP dissociation. The kinetic results suggest that the initial contact of EF-Ts with helix D of EF-Tu weakens binding interactions around the guanine base, whereas contacts of EF-Ts with the phosphate binding side that promotes the release of the phosphate moiety of GDP appear to take place later. This "base-side-first" mechanism of guanine nucleotide release resembles that found for Ran x RCC1 and differs from mechanisms described for other GTPase x GEF complexes where interactions at the phosphate side of the nucleotide are released first.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
22
pubmed:volume
277
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6032-6
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Mechanism of elongation factor (EF)-Ts-catalyzed nucleotide exchange in EF-Tu. Contribution of contacts at the guanine base.
pubmed:affiliation
Institute of Physical Biochemistry, University of Witten/Herdecke, 58448 Witten, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't