Translation initiation from the ribosomal A site or the P site, dependent on the conformation of RNA pseudoknot I in dicistrovirus RNAs

available in PMC 2010 July 31.

Bibliographic Details
Main Authors: Kamoshita, Nobuhiko (Contributor), Nomoto, Akio (Author), Rajbhandary, Uttam L (Author)
Other Authors: Massachusetts Institute of Technology. Department of Biology (Contributor), Rajbhandary, Uttam L. (Contributor)
Format: Article
Language:English
Published: Elsevier B.V., 2012-10-30T15:10:18Z.
Subjects:
Online Access:Get fulltext
LEADER 01960 am a22002413u 4500
001 74505
042 |a dc 
100 1 0 |a Kamoshita, Nobuhiko  |e author 
100 1 0 |a Massachusetts Institute of Technology. Department of Biology  |e contributor 
100 1 0 |a Rajbhandary, Uttam L.  |e contributor 
100 1 0 |a Kamoshita, Nobuhiko  |e contributor 
700 1 0 |a Nomoto, Akio  |e author 
700 1 0 |a Rajbhandary, Uttam L  |e author 
245 0 0 |a Translation initiation from the ribosomal A site or the P site, dependent on the conformation of RNA pseudoknot I in dicistrovirus RNAs 
260 |b Elsevier B.V.,   |c 2012-10-30T15:10:18Z. 
856 |z Get fulltext  |u http://hdl.handle.net/1721.1/74505 
520 |a available in PMC 2010 July 31. 
520 |a Translation initiation of the second ORF of insect dicistrovirus RNA depends on an internal ribosomal entry site (IRES) in its intergenic region (IGR) and is exceptional in using a codon other than AUG and in not using the canonical initiator methionine tRNA. Studies in vitro suggest that pseudoknot I (PKI) immediately preceding the initiation codon occupies the ribosomal P site and that an elongator tRNA initiates translation from the ribosomal A site. Using dicistronic reporters carrying mutations in the initiation codon of the second ORF and mutant elongator or initiator tRNAs capable of reading these codons, we provide direct evidence for initiation from the A site in mammalian cells and, under certain conditions, also from the P site. Initiation from the A but not the P site requires PKI. Thus, PKI structure may be dynamic, and optimal IGR IRES-mediated translation of dicistroviral RNAs may require trans-acting factors to stabilize PKI. 
520 |a National Institutes of Health (U.S.) (grant GM17151) 
520 |a Japan. Ministry of Education, Culture, Sports, Science and Technology (Grants-In-Aid for Scientific Research on Priority Areas) 
546 |a en_US 
655 7 |a Article 
773 |t Molecular Cell