Phosphorylated claspin interacts with a phosphate-binding site in the kinase domain of Chk1 during ATR-mediated activation.

@article{Jeong2003PhosphorylatedCI,
  title={Phosphorylated claspin interacts with a phosphate-binding site in the kinase domain of Chk1 during ATR-mediated activation.},
  author={S Jeong and Akiko Kumagai and Joon Jae Lee and William G. Dunphy},
  journal={The Journal of biological chemistry},
  year={2003},
  volume={278 47},
  pages={46782-8}
}
Claspin is essential for the ATR-dependent activation of Chk1 in Xenopus egg extracts containing incompletely replicated or UV-damaged DNA. The activated form of Claspin contains two repeated phosphopeptide motifs that mediate its binding to Chk1. We show that these phosphopeptide motifs bind to Chk1 by means of its N-terminal kinase domain. The binding site on Chk1 involves a positively charged cluster of amino acids that contains lysine 54, arginine 129, threonine 153, and arginine 162… CONTINUE READING