Related Experiment Videos
Characterization of reverse transcriptase from feline immunodeficiency virus
T W North1, R C Cronn, K M Remington
1Division of Biological Sciences, University of Montana, Missoula 59812.
Insights
Feline immunodeficiency virus (FIV) reverse transcriptase shares similarities with human immunodeficiency virus (HIV) reverse transcriptase in function but differs significantly in primary sequence.
Area of Science:
- Virology
- Molecular Biology
- Biochemistry
Background:
- Feline immunodeficiency virus (FIV) is a lentivirus that infects cats.
- Reverse transcriptase is a key enzyme in the replication cycle of retroviruses, including FIV and HIV.
- Understanding viral enzyme structure and function is crucial for developing antiviral therapies.
Purpose of the Study:
- To purify and characterize the reverse transcriptase enzyme from FIV.
- To compare the properties of FIV reverse transcriptase with that of human immunodeficiency virus type 1 (HIV) reverse transcriptase.
Main Methods:
- Purification of FIV reverse transcriptase using DEAE-cellulose and phosphocellulose chromatography.
- Analysis of enzyme molecular weight (Mr) and polypeptide composition.
- Peptide mapping to assess primary sequence differences.
- Comparison of template specificity and Mg2+ requirements.
Main Results:
- FIV reverse transcriptase was purified as a single protein of Mr 67,000, with a Mr 54,000 fragment observed under non-optimized conditions.
- HIV reverse transcriptase consists of a Mr 66,000 polypeptide, with a Mr 51,000 fragment under similar conditions.
- FIV and HIV reverse transcriptases exhibited similar template specificity and Mg2+ requirements.
- Peptide mapping revealed substantial differences in the primary sequence of FIV and HIV reverse transcriptases.
Conclusions:
- FIV reverse transcriptase is biochemically similar to HIV reverse transcriptase in enzymatic activity.
- Despite functional similarities, significant primary sequence divergence exists between FIV and HIV reverse transcriptases.
- These findings contribute to the understanding of lentiviral enzyme evolution and diversity.
Abstract:
Reverse transcriptase has been purified from feline immunodeficiency virus (FIV) by DEAE-cellulose and phosphocellulose chromatography. The purified enzyme consists of a single protein with a Mr of 67,000. When proteolysis is not minimized during purification, a fragment of Mr 54,000 is also observed. This is similar to the reverse transcriptase from human immunodeficiency virus type 1 (HIV), which consists of a polypeptide of Mr 66,000; when proteolysis is not minimized during purification, a fragment of Mr 51,000 is also observed. In direct comparisons, the FIV reverse transcriptase is very similar to the HIV reverse transcriptase in template specificity and requirements for Mg2+. In contrast to these similarities, the FIV and HIV reverse transcriptases are substantially different in primary sequence, as determined by peptide mapping.