Mammalian retrovirus-associated RNase H is virus coded

Area of Science:

• Virology
• Molecular Biology
• Biochemistry

Background:

• Rauscher murine leukemia virus is a type C retrovirus.
• Reverse transcriptase is a key enzyme in retroviral replication.
• RNase H is a domain of reverse transcriptase with enzymatic activity.

Purpose of the Study:

• To determine if the RNase H activity of Rauscher murine leukemia virus is a virus-coded function.
• To investigate the thermal stability of RNase H in a temperature-sensitive mutant of the virus.

Main Methods:

• Utilized a temperature-sensitive mutant of Rauscher murine leukemia virus.
• Assayed RNase H enzymatic activity at different temperatures.
• Compared enzyme activity between wild-type and mutant viruses.

Main Results:

• The RNase H activity of the temperature-sensitive mutant was found to be thermolabile (heat-sensitive).
• This thermolability indicates that the enzyme's function is compromised at elevated temperatures.
• The results support the hypothesis that RNase H is encoded by the virus.

Conclusions:

• RNase H is a virus-coded function of the Rauscher murine leukemia virus reverse transcriptase.
• The temperature-sensitive mutation affects the stability of the RNase H activity.
• This study provides evidence for the genetic basis of enzymatic functions in retroviral reverse transcriptase.