Sequences of ribosome binding sites from the large size class of reovirus mRNA

Area of Science:

• Molecular Biology
• Virology
• Genetics

Background:

• Eukaryotic translation initiation is a complex process involving the ribosome binding to messenger RNA (mRNA).
• The 5' cap structure (m7G cap) of eukaryotic mRNAs plays a crucial role in initiating translation.
• Understanding the specific sequences that mediate ribosome binding is essential for deciphering gene expression regulation.

Purpose of the Study:

• To determine the precise sequences of ribosome binding sites on reovirus large-sized mRNAs.
• To investigate the role of the m7G cap and initiator codon in reovirus mRNA translation.
• To compare reovirus initiation patterns with known eukaryotic translation initiation consensus sequences.

Main Methods:

• Isolation of ribosome-protected fragments from sparsomycin-blocked 80S initiation complexes.
• Sequencing of oligonucleotides protected by ribosomes to identify binding sites.
• Analysis of the determined sequences for characteristic features of translation initiation sites.

Main Results:

• Ribosome-protected fragments were successfully recovered from two large reovirus mRNAs.
• The determined sequences revealed the presence of the m7G cap and a centrally positioned AUG initiator codon.
• An adenine residue was consistently found three nucleotides upstream of the AUG codon.

Conclusions:

• The ribosome binding site on reovirus mRNAs includes the m7G cap and an AUG codon.
• The identified initiation pattern, [AG]NNAUG, is conserved in reovirus and typical of most eukaryotic mRNAs.
• This finding provides insights into the conserved mechanisms of translation initiation in viruses and eukaryotes.