Kelch proteins (and Kelch-like proteins) are a widespread group of proteins that contain multiple Kelch motifs. The kelch domain generally occurs as a set of five to seven kelch repeats that form a β-propeller tertiary structure. Kelch-repeat β-propellers are generally involved in protein-protein interactions, though the large diversity of domain architectures and limited sequence identity between kelch motifs make characterisation of the kelch superfamily difficult. Kelch like proteins are known to act as substrate adaptors for Cullin 3 ubiquitin ligases.
