Inverted complementary terminal sequences in single-stranded RNAs and snap-back RNAs from vesicular stomatitis...

Area of Science:

• Virology
• Molecular Biology
• RNA Structure

Background:

• Defective interfering (DI) particles are generated during viral replication and possess unique RNA genomes.
• Understanding the structure of DI RNAs is crucial for elucidating their replication and interference mechanisms.

Purpose of the Study:

• To investigate the structural properties of complementary single-stranded RNAs from VSV DI particles.
• To determine the presence and nature of terminal sequences in VSV DI RNAs.

Main Methods:

• Electron microscopy to visualize RNA structures.
• Formamide-gel electrophoresis to analyze RNA forms.
• RNase digestion to isolate and characterize terminal sequences.
• RNA denaturation and rapid cooling to induce secondary structures.

Main Results:

• VSV DI RNAs can form monomeric and multimeric circular and linear double-stranded structures.
• A significant proportion of DI RNA molecules exhibit circularization, suggesting inverted complementary terminal sequences.
• RNase digestion yielded specific sized fragments (60-70 nt and 135-170 nt), confirming the presence of terminal structures.
• Snap-back DI RNAs possess inverted complementary sequences at both ends of plus and minus strands.

Conclusions:

• VSV DI RNAs contain inverted complementary terminal sequences that facilitate the formation of snap-back structures.
• These terminal sequences are likely involved in the formation of circular and linear double-stranded RNA molecules.
• A covalent linkage near complementary terminal sequences may exist in snap-back DI RNA molecules.