This family of proteins represents the C terminal SARAH domain of Mst1. SARAH controls apoptosis and cell cycle arrest via the Ras, RASSF, MST pathway. The Mst1 SARAH domain interacts with Rassf1 and Rassf5 by forming a heterodimer which mediates the apoptosis process [1].

1: Structural insight into dimeric interaction of the SARAH domains from Mst1 and RASSF family proteins in the apoptosis pathway. Hwang E, Ryu KS, Paakkonen K, Guntert P, Cheong HK, Lim DS, Lee JO, Jeon YH, Cheong C; Proc Natl Acad Sci U S A. 2007;104:9236-9241. PMID:17517604