The clip domain is a structural/regulatory unit in many arthropod serine proteases [1]. The clip domain super-family also includes serine protease homologs (SPHs) [2]. This entry describes clip domains in the SPHs (CLIP subfamily A), which belong to group-3. SPHs usually carry between 1 to 5 clip domains [3]. One of the most prominent family members is masquerade (mas). Deletion in drosophila models lead to defects in somatic muscle attachment and in the formation of the nervous system during embryogenesis [4].

1: Serine proteases and their homologs in the Drosophila melanogaster genome: an initial analysis of sequence conservation and phylogenetic relationships. Ross J, Jiang H, Kanost MR, Wang Y; Gene. 2003;304:117-131. PMID:12568721

2: Clip-domain serine proteases as immune factors in insect hemolymph. Kanost MR, Jiang H; Curr Opin Insect Sci. 2015;11:47-55. PMID:26688791

3: Sequence conservation, phylogenetic relationships, and expression profiles of nondigestive serine proteases and serine protease homologs in Manduca sexta. Cao X, He Y, Hu Y, Zhang X, Wang Y, Zou Z, Chen Y, Blissard GW, Kanost MR, Jiang H; Insect Biochem Mol Biol. 2015;62:51-63. PMID:25530503

4: Mutations in masquerade, a novel serine-protease-like molecule, affect axonal guidance and taste behavior in Drosophila. Murugasu-Oei B, Balakrishnan R, Yang X, Chia W, Rodrigues V; Mech Dev. 1996;57:91-101. PMID:8817456