A complex RNA sequence determines the internal initiation of encephalomyocarditis virus RNA translation.
Translation initiation on EMCV RNA occurs via binding of ribosomes to an internal sequence within the 5' noncoding region. To investigate the organization of the internal ribosome entry site (IRES) we have determined the translational efficiencies of a series of deletion mutants within the 5' noncoding region of EMCV RNA. Three functional regions have been distinguished: a sequence between nts 315-484 and the upper parts of the double-helical structural domains III (nts 488-647) and IV (nts 701-763). The first one greatly enhances translation, but is not absolutely necessary for internal initiation. The other two regions are indispensable to this process. A sequence within domain IV determines inhibition of in vitro translation of mRNAs with 5'-terminal dependent initiation. It is proposed to interact with a translational factor(s) common to the internal and 5'-terminal dependent initiation.
Evstafieva
A G
AG
A.N. Belosersky Laboratory, Moscow State University, USSR.
Ugarova
T Y
TY
Chernov
B K
BK
Shatsky
I N
IN
D001665:Binding Sites; D001667:Binding, Competitive; D003001:Cloning, Molecular; D004252:DNA Mutational Analysis; D004686:Encephalomyocarditis virus / Q000235:genetics*; D006860:Hydrogen Bonding; D015394:Molecular Structure; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics* / Q000648:ultrastructure; D012367:RNA, Viral / Q000235:genetics* / Q000648:ultrastructure; D012045:Regulatory Sequences, Nucleic Acid; D015183:Restriction Mapping; D012270:Ribosomes / Q000378:metabolism*
D012333:RNA, Messenger; D012367:RNA, Viral