Publication Date:
1998-05-09
Description:
High-fidelity transfers of genetic information in the central dogma can be achieved by a reaction called editing. The crystal structure of an enzyme with editing activity in translation is presented here at 2.5 angstroms resolution. The enzyme, isoleucyl-transfer RNA synthetase, activates not only the cognate substrate L-isoleucine but also the minimally distinct L-valine in the first, aminoacylation step. Then, in a second, "editing" step, the synthetase itself rapidly hydrolyzes only the valylated products. For this two-step substrate selection, a "double-sieve" mechanism has already been proposed. The present crystal structures of the synthetase in complexes with L-isoleucine and L-valine demonstrate that the first sieve is on the aminoacylation domain containing the Rossmann fold, whereas the second, editing sieve exists on a globular beta-barrel domain that protrudes from the aminoacylation domain.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Nureki, O -- Vassylyev, D G -- Tateno, M -- Shimada, A -- Nakama, T -- Fukai, S -- Konno, M -- Hendrickson, T L -- Schimmel, P -- Yokoyama, S -- GM15539/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1998 Apr 24;280(5363):578-82.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biophysics and Biochemistry, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9554847" target="_blank"〉PubMed〈/a〉
Keywords:
Adenosine Monophosphate
;
Binding Sites
;
Crystallography, X-Ray
;
Escherichia coli/enzymology
;
Hydrogen Bonding
;
Hydrolysis
;
Isoleucine/*metabolism
;
Isoleucine-tRNA Ligase/*chemistry/metabolism
;
Models, Chemical
;
Models, Molecular
;
Molecular Sequence Data
;
Mutagenesis
;
Protein Conformation
;
Protein Folding
;
Protein Structure, Secondary
;
RNA, Transfer, Ile/metabolism
;
Substrate Specificity
;
Thermus thermophilus/enzymology
;
Transfer RNA Aminoacylation
;
Valine/*metabolism
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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