Yuefeng Wang, Igor Filippov, Christian Richter, Rensheng Luo and Richard W. Kriwacki
Cold feat. A combined strategy to obtain the backbone assignments of an intrinsically unstructured protein, p21-KID, bound to its biological target, Cdk2/cyclin A, is presented. In order to overcome the challenges associated with the high molecular weight and low solubility of the ternary complex, we used perdeuteration, specific amino acid isotope labeling, TROSY, and cryogenic NMR probes at high magnetic-field strengths. In addition, we studied binary subcomplexes; this allowed resonance assignments to be made in stages.