Pulling Genetic RNA out of Tobacco Mosaic Virus Using Single-Molecule Force Spectroscopy

RNA−coat protein interactions in intact tobacco mosaic virus have been investigated for the first time directly on the single-molecule level by pulling the genetic RNA step by step out of the helical groove formed by its protein coat. The effects of pulling speed and pH on RNA−protein interactions are presented. In addition, the rebinding behavior of the detached RNA with the protein coat is discussed. Our results demonstrate the possibility of studying nucleic acid−protein interactions in more complicated systems using AFM-based single-molecule force spectroscopy.