Skip Navigation

This Article
Right arrow Full Text Freely available
Right arrow Print PDF (96K) Freely available
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Right arrow Commercial Re-use Guidelines
for Open Access NAR Content
Google Scholar
Right arrow Articles by Jakubowski, H
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Jakubowski, H
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Nucleic Acids Research, Vol 24, Issue 13 2505-2510, Copyright © 1996 by Oxford University Press

ARTICLES

Proofreading in trans by an aminoacyl-tRNA synthetase: a model for single site editing by isoleucyl-tRNA synthetase

H Jakubowski
Department of Microbiology and Molecular Genetics, UMDNJ-New Jersey Medical School, Newark, NJ 07103, USA.

Editing of errors in amino acid selection by an aminoacyl-tRNA synthetase prevents attachment of incorrect amino acids to tRNA, thereby greatly enhancing accuracy of translation of the genetic code. Editing of the non-protein amino acid homocysteine, a frequent type of an error-correcting process, involves reaction of the side chain sulfhydryl group of homocysteine with its activated carboxyl group forming a cyclic thioester, homocysteine thiolactone. Here, it is shown that isoleucyl-tRNA synthetase (IleRS), which occasionally misactivates homocysteine in vitro and in vivo, catalyzes reactions of activated isoleucine with organic thiols (analogues of the side chain of homocysteine). That these enzymatic reactions occur between Ile-tRNAIle or Ile-AMP (bound in the synthetic sub-site) and a thiol (an analogue of the side chain of homocysteine, bound in the editing sub-site), indicates that the two sub-sites are physically close on the surface of IleRS, forming a single synthetic/editing active site of the enzyme. Although IleRS.Val-AMP undergoes thiolysis as efficiently as do IleRS.Ile-AMP and IleRS.Ile-tRNAIle, IleRS.Val-tRNAIle does not react with thiols. These and other data suggest that the mischarged valine residue in IleRS.Val-tRNAIle is, most likely, positioned off the enzyme.
Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 J. Nutr.Home page
H. Jakubowski
Translational Accuracy of Aminoacyl-tRNA Synthetases: Implications for Atherosclerosis
J. Nutr., November 1, 2001; 131(11): 2983S - 2987.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
H. Jakubowski
Translational Incorporation of S-Nitrosohomocysteine into Protein
J. Biol. Chem., July 14, 2000; 275(29): 21813 - 21816.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
H. Jakubowski
Amino Acid Selectivity in the Aminoacylation of Coenzyme A and RNA Minihelices by Aminoacyl-tRNA Synthetases
J. Biol. Chem., November 3, 2000; 275(45): 34845 - 34848.
[Abstract] [Full Text] [PDF]


Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.