Blood coagulation factors V and VIII contain a C-terminal, twice repeated, domain of about 150 amino acids, which is often called "C2-like domain" (that is unrelated to the C2 domain). In the Dictyostelium discoideum (Slime mold) cell adhesion protein discoidin, a related domain, named discoidin I-like domain, DLD, or DS, has been found which shares a common C-terminal region of about 110 amino acids with the FA58C domain, but whose N-terminal 40 amino acids are much less conserved. Similar domains have been detected in other extracellular and membrane proteins.[2][3][4] In coagulation factors V and VIII the repeated domains compose part of a larger functional domain which promotes binding to anionic phospholipids on the surface of platelets and endothelial cells.[5] The C-terminal domain of the second FA58C repeat (C2) of coagulation factor VIII has been shown to be responsible for phosphatidylserine-binding and essential for activity.[6][7] FA58C contains two conserved cysteines in most proteins, which link the extremities of the domain by a disulfide bond.[8][9][10] A further disulfide bond is located near the C-terminal of the second FA58C domain in MFGM Q08431.[10]
^Couto JR, Taylor MR, Godwin SG, Ceriani RL, Peterson JA (1996). "Cloning and sequence analysis of human breast epithelial antigen BA46 reveals an RGD cell adhesion sequence presented on an epidermal growth factor-like domain". DNA Cell Biol. 15 (4): 281–286. doi:10.1089/dna.1996.15.281. PMID8639264.
^Mann KG, Xue J, Kalafatis M (1993). "Determination of the disulfide bridges in factor Va light chain". Biochemistry. 32 (22): 5917–5923. doi:10.1021/bi00071a002. PMID8504111.