<it>Tomato leaf curl Kerala virus </it>(ToLCKeV) AC3 protein forms a higher order oligomer and enhances ATPase activity of replication initiator protein (Rep/AC1)

• Main Authors: Mukherjee Sunil K, Choudhury Nirupam R, Pasumarthy Kalyan K
• Format: Article
• Language: English
• Published: BMC 2010-06-01
• Series: Virology Journal
• Online Access: http://www.virologyj.com/content/7/1/128
• ISSN: 1743-422X

<p>Abstract</p> <p>Background</p> <p>Geminiviruses are emerging plant viruses that infect a wide variety of vegetable crops, ornamental plants and cereal crops. They undergo recombination during co-infections by different species of geminiviruses and give rise to more virulent species. Antiviral strategies targeting a broad range of viruses necessitate a detailed understanding of the basic biology of the viruses. ToLCKeV, a virus prevalent in the tomato crop of Kerala state of India and a member of genus Begomovirus has been used as a model system in this study.</p> <p>Results</p> <p>AC3 is a geminiviral protein conserved across all the begomoviral species and is postulated to enhance viral DNA replication. In this work we have successfully expressed and purified the AC3 fusion proteins from <it>E. coli</it>. We demonstrated the higher order oligomerization of AC3 using sucrose gradient ultra-centrifugation and gel-filtration experiments. In addition we also established that ToLCKeV AC3 protein interacted with cognate AC1 protein and enhanced the AC1-mediated ATPase activity in vitro.</p> <p>Conclusions</p> <p>Highly hydrophobic viral protein AC3 can be purified as a fusion protein with either MBP or GST. The purification method of AC3 protein improves scope for the biochemical characterization of the viral protein. The enhancement of AC1-mediated ATPase activity might lead to increased viral DNA replication.</p>