Purified GST, GST-VP1 and GST-VP3 proteins were diluted to 500 ng/μl with DNA-binding buffer and 500 ng of proteins were mixed with 100 ng of each DNA variant in a total of 20 μl of DNA-binding buffer. Then, each mixture was incubated for 30 min under 37 °C. The resulting sample was subjected to electrophoresis using a 0.8% agarose gel in a TAE buffer and, then the DNA was stained with ethidium bromide for the analysis of DNA migration.