Publication Date:
1994-04-08
Description:
Editing reactions are essential for the high fidelity of information transfer in processes such as replication, RNA splicing, and protein synthesis. The accuracy of interpretation of the genetic code is enhanced by the editing reactions of aminoacyl transfer RNA (tRNA) synthetases, whereby amino acids are prevented from being attached to the wrong tRNAs. Amino acid discrimination is achieved through sieves that may overlap with or coincide with the amino acid binding site. With the class I Escherichia coli isoleucine tRNA synthetase, which activates isoleucine and occasionally misactivates valine, as an example, a rationally chosen mutant enzyme was constructed that lacks entirely its normal strong ability to distinguish valine from isoleucine by the initial amino acid recognition sieve. The misactivated valine, however, is still eliminated by hydrolytic editing reactions. These data suggest that there is a distinct sieve for editing that is functionally independent of the amino acid binding site.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Schmidt, E -- Schimmel, P -- GM 15539/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1994 Apr 8;264(5156):265-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biology, Massachusetts Institute of Technology, Cambridge 02139.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/8146659" target="_blank"〉PubMed〈/a〉
Keywords:
Adenosine Triphosphate/metabolism
;
Binding Sites
;
Escherichia coli/enzymology
;
Isoleucine/*metabolism
;
Isoleucine-tRNA Ligase/chemistry/genetics/*metabolism
;
Kinetics
;
Mutation
;
Protein Structure, Secondary
;
*RNA Editing
;
RNA, Transfer, Ile/metabolism
;
Valine/*metabolism
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
