This family appears to be the cytoplasmic domain of the calcium-activated chloride-channel, anoctamin, protein. It is responsible for creating the homodimeric architecture of the chloride-channel proteins.

1: Anoctamins are a family of Ca2+-activated Cl- channels. Tian Y, Schreiber R, Kunzelmann K; J Cell Sci. 2012;125:4991-4998. PMID:22946059

2: Identification of a dimerization domain in the TMEM16A calcium-activated chloride channel (CaCC). Tien J, Lee HY, Minor DL Jr, Jan YN, Jan LY; Proc Natl Acad Sci U S A. 2013;110:6352-6357. PMID:23576756