Linked Life Data

19656186

Source:http://linkedlifedata.com/resource/pubmed/id/19656186

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
17
pubmed:dateCreated
2009-8-21
pubmed:databankReference
pubmed:abstractText
The ATP-pyrophosphate exchange reaction catalyzed by Arg-tRNA, Gln-tRNA and Glu-tRNA synthetases requires the assistance of the cognate tRNA. tRNA also assists Arg-tRNA synthetase in catalyzing the pyrophosphorolysis of synthetic Arg-AMP at low pH. The mechanism by which the 3'-end A76, and in particular its hydroxyl group, of the cognate tRNA is involved with the exchange reaction catalyzed by those enzymes has yet to be established. We determined a crystal structure of a complex of Arg-tRNA synthetase from Pyrococcus horikoshii, tRNA(Arg)(CCU) and an ATP analog with Rfactor = 0.213 (Rfree = 0.253) at 2.0 A resolution. On the basis of newly obtained structural information about the position of ATP bound on the enzyme, we constructed a structural model for a mechanism in which the formation of a hydrogen bond between the 2'-OH group of A76 of tRNA and the carboxyl group of Arg induces both formation of Arg-AMP (Arg + ATP --> Arg-AMP + pyrophosphate) and pyrophosphorolysis of Arg-AMP (Arg-AMP + pyrophosphate --> Arg + ATP) at low pH. Furthermore, we obtained a structural model of the molecular mechanism for the Arg-tRNA synthetase-catalyzed deacylation of Arg-tRNA (Arg-tRNA + AMP --> Arg-AMP + tRNA at high pH), in which the deacylation of aminoacyl-tRNA bound on Arg-tRNA synthetase and Glu-tRNA synthetase is catalyzed by a quite similar mechanism, whereby the proton-donating group (-NH-C+(NH2)2 or -COOH) of Arg and Glu assists the aminoacyl transfer from the 2'-OH group of tRNA to the phosphate group of AMP at high pH.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1742-4658
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
276
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4763-79
pubmed:dateRevised
2010-2-12
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Modeling of tRNA-assisted mechanism of Arg activation based on a structure of Arg-tRNA synthetase, tRNA, and an ATP analog (ANP).
pubmed:affiliation
Department of Chemistry and Biochemistry, Graduate School of Humanities and Sciences, Ochanomizu University, Tokyo, Japan. konno.michiko@ocha.ac.jp
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't