Figure 3. Possible roles for CSB in mitochondrial transcription.
CSB was recently shown to stimulate the RNA elongation activity of the mitochondrial polymerase. In this regard CSB could act either as a DNA annealing enzyme closing the transcription bubble after the RNA polymerase. Alternatively, CSB has been shown to be able to displace TFAM from the DNA strand. In this regard CSB could act to remove bound proteins from the DNA strand in front of the polymerase thereby facilitating transcription.