Proteins containing this domain are checkpoint proteins involved in cell division. This region has been shown to be essential for the binding of the binding of BUB1 and MAD3 to CDC20p [1].

1: MAD3 encodes a novel component of the spindle checkpoint which interacts with Bub3p, Cdc20p, and Mad2p. Hardwick KG, Johnston RC, Smith DL, Murray AW; J Cell Biol 2000;148:871-882. PMID:10704439