Reovirus guanylyltransferase is L2 gene product lambda 2.

Area of Science:

• Virology
• Molecular Biology
• Enzymology

Background:

• Reovirus RNA capping is essential for viral gene expression.
• Guanylyltransferase plays a key role in the RNA 5' capping process.
• Understanding the enzymatic activity of reovirus guanylyltransferase is critical.

Purpose of the Study:

• To investigate the enzymatic activity of reovirus guanylyltransferase.
• To characterize the role of the enzyme-GMP intermediate in guanylation.
• To identify the viral protein responsible for guanylyltransferase activity.

Main Methods:

• Studying reovirus guanylyltransferase as a covalent enzyme-GMP intermediate.
• In vitro guanylation of acceptor molecules.
• Assaying guanylyltransferase activity.

Main Results:

• Reovirus guanylyltransferase successfully guanylated acceptor molecules in vitro.
• Authentic cap structures were produced.
• Guanylyltransferase activity was specifically associated with lambda 2, a 140-kilodalton protein.

Conclusions:

• The L2 gene segment product, lambda 2, possesses guanylyltransferase activity.
• This activity is responsible for generating authentic reovirus cap structures.
• The enzyme functions via a covalent enzyme-GMP intermediate.