Backbone and side chain assignments of human cell cycle regulatory protein S-phase kinase-associated protein 1.

Ubiquitination of proteins is required to regulate several cellular mechanisms in cells. Skp1-Cullin-1-F-box (SCF), the largest family of the RING E3 ligases, recognizes and carries out the poly-ubiquitination of many substrate proteins. SCF E3 ligase is a multi-component protein complex, and the human S-phase kinase-associated protein 1 (Skp1) is the adapter protein, which binds and presents the substrate binding protein F-box (FBP) to the rest of the E3 ligase. Several crystallographic studies have solved the partial structure of Skp1 in complex with various FBPs, but there is no structure of standalone Skp1. Understanding the conformational and structural properties of Skp1 with and without FBPs is required to understand the complete mechanism of poly-ubiquitination. Here, we report ~90 % backbone and 64 % side chain (1)H, (13)C, (15)N assignments of Skp1 protein using various double and triple resonance NMR experiments.