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Title: Identification of the initiation site of poliovirus polyprotein synthesis

The complete nucleotide sequence of poliovirus RNA has a long open reading frame capable of encoding the precursor polyprotein NCVPOO. The first AUG codon in this reading frame is located 743 nucleotides from the 5' end of the RNA and is preceded by eight AUG codons in all three reading frames. Because all proteins that map at the amino terminus of the polyprotein (P1-1a, VPO, and VP4) are blocked at their amino termini and previous studies of ribosome binding have been inconclusive, direct identification of the initiation site of protein synthesis was difficult. We separated and identified all of the tryptic peptides of capsid protein VP4 and correlated these peptides with the amino acid sequence predicted to follow the AUG codon at nucleotide 743. Our data indicate that VP4 begins with a blocked glycine that is encoded immediately after the AUG codon at nucleotide 743. An S1 nuclease analysis of poliovirus mRNA failed to reveal a splice in the 5' region. We concluded that synthesis of poliovirus polyprotein is initiated at nucleotide 743, the first AUG codon in the long open reading frame.
Authors:
 [1] ; ; ; ;
  1. (State Univ. of New York, Stony Brook)
Publication Date:
OSTI Identifier:
6779380
Resource Type:
Journal Article
Resource Relation:
Journal Name: J. Virol.; (United States); Journal Volume: 42:3
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; POLIO VIRUS; MOLECULAR BIOLOGY; PROTEINS; BIOSYNTHESIS; CODONS; NUCLEOTIDES; MICROORGANISMS; ORGANIC COMPOUNDS; PARASITES; SYNTHESIS; VIRUSES 550700* -- Microbiology; 550200 -- Biochemistry