The characterization of a recombinant virophage integrase
Virophages are satellite-like dsDNA viruses that parasitize giant viruses of the family Mimiviridae. Mavirus is the second virophage discovered that associates with its host virus Cafeteria roenbergensis Virus (CroV). When co-infecting their common host cell Cafeteria roenbergensis, a marine zooplankton that is widely spread throughout the oceans, mavirus will inhibit CroV’s replication. In addition, mavirus was shown to share high similarities to the Maverick/Polinton eukaryotic DNA transposons. A coding sequence in mavirus genome (MV02) reveals high homology to retroviral integrases such as those found in HIVs. The putative integrase MV02 is predicted to integrate mavirus DNA into the host genome. In order to characterize MV02 and prove it is indeed an integrase, large amounts of protein need to be obtained and three functional aspects must be studied that include: DNA binding, DNA processing, and DNA strand transfer. In this study, large amount of recombinant MV02 has been expressed and purified to high homogeneity. The recombinant MV02 has been tested for its DNA binding using chromatographic techniques and gel shift assays. These experiments build the foundation for future structural studies as well as further functional analysis such as testing DNA processing and strand transfer capabilities of recombinant MV02. Proving MV02 is an integrase will not only reveal an aspect of the virophage infection process, but will also shed light on the evolutionary relationship between the mavirus and the Maverick/Polinton transposons. Due to high similarity between MV02 and retroviral integrase and limited structural and functional knowledge of the latter, new information obtained by studying mavirus integrase will shed new insights for drug development against AIDS.
Chacon, Martin Christopher, "The characterization of a recombinant virophage integrase" (2016). ETD Collection for University of Texas, El Paso. AAI10151228.