POTATO YELLOW MOSAIC GEMINIVIRUS AC2 PROTEIN IS A SEQUENCE NONSPECIFIC DNA-BINDING PROTEIN

The AC2 protein of potato yellow mosaic geminivirus (PYMV) is by analo gy with related geminiviruses thought to be a transcriptional activato r protein. We have over-expressed the AC2 open reading frame in E. col i and purified the protein from bacterial extracts to near homogeneity . We have studied the interaction of the AC2 protein with DNA and from gel retardation assays shown that it binds both double-stranded (ds) and single-stranded (ss) DNA non-specifically. The binding to PYMV int ergenic region ds DNA appeared to be independent of the presence of zi nc ions and did not require the protein to be phosphorylated.