Nucleic acid binding with a protein product of the first open reading frame of retrotransposon gypsy (mdg4)

A DNA fragment with the first open reading frame (ORF) of retrotransposon g ypsy (mdg4) was cloned and expressed in Escherichia coli, and its protein p roduct was purified. The recombinant protein was shown to bind with its own mRNA and with DNA, the affinity for ssDNA bing higher than for dsDNA. The binding constant was estimated with RNA. The structure of the putative nucl eic acid-binding domain suggests that the protein is more similar to the co re proteins of spumaviruses of the family Retroviridae that to those of oth er retroviruses.