The Mu enhancer is functionally asymmetric both in cis and in trans. Topological selectivity of Mu transposition is enhancer-independent.

@article{Jiang2001TheME,
  title={The Mu enhancer is functionally asymmetric both in cis and in trans. Topological selectivity of Mu transposition is enhancer-independent.},
  author={Hualiang Jiang and Rasika M. Harshey},
  journal={The Journal of biological chemistry},
  year={2001},
  volume={276 6},
  pages={4373-81}
}
Mu DNA transposition from a negatively supercoiled DNA substrate requires interaction of an enhancer element with the left (attL) and right (attR) ends of Mu. The orientation of the L and R ends with respect to each other (inverted) and with respect to the enhancer is normally inviolate. We show that when the enhancer is provided in trans as a linear fragment, the head to head orientation of the L/R ends is still required. Each functional half of the linear enhancer maintains the same "cross… CONTINUE READING