PROSITE documentation PDOC00282

Seminal vesicle protein I repeats signature

Seminal vesicle protein I (SVP-1) [1] is one of the four major secretory proteins secreted by guinea-pig seminal vesicle epithelium. It is a clotting protein that serves as the substrate in the formation of the copulatory plug. Covalent clotting of this protein is catalyzed by a transglutaminase and involves the formation of γ-glutamyl-epsilon-lysine crosslinks. SVP-1 sequence contains eight repeats of a twenty four amino acid residue domain. There are seven invariant residues in these repeats, three of them (two lysines and one glutamine) probably participate in the cross-links. The pattern we have developed comprises positions 1 to 19 of the domain and includes the three cross-linking residues.

This pattern is also present twice [2] in the N-terminal region of the precursor of human skin elafin, an inhibitor of elastase as well as in the precursor of pig sodium/potassium atpase inhibitor SPAI-2.