@article{varadan2002structural,
  title={Structural properties of polyubiquitin chains in solution},
  author={Varadan, Ranjani and Walker, Olivier and Pickart, Cecile and Fushman, David},
  journal={Journal of molecular biology},
  volume={324},
  number={4},
  pages={637--647},
  year={2002},
  publisher={Elsevier}
}