p23_like domain similar to the C-terminal (tail) domain of vertebrate Melusin and related proteins. Melusin's tail domain interacts with the cytoplasmic domain of beta1-A and beta1-D isoforms of beta1 integrin, it does not bind other integrin beta subunits. Melusin is a muscle-specific protein expressed in skeletal and cardiac muscles but not in smooth muscle or other tissues. It is needed for heart hypertrophy following mechanical overload. The integrin-binding portion of this domain appears to be sequestered in the full length melusin protein, Ca2+ may modulate the protein's conformation exposing this binding site. This group includes Chordc1, also known as Chp-1, which is conserved from vertebrates to humans. Mammalian Chordc1 interacts with the heat shock protein (HSP) Hsp90 and is implicated in circadian and/or homeostatic mechanisms in the brain. The N-terminal portions of proteins belonging to this group contain two cysteine and histidine rich domain (CHORD) domains.