The zona pellucida (ZP) domain is a protein polymerisation module of ~260 amino acid module, which is found at the C-terminus of many secreted eukaryotic glycoproteins that play fundamental roles in development, hearing, immunity, and cancer PMID:1313375,PMID:12021773,PMID:12878193,PMID:15079052.

The ZP module is not only conserved in egg coat components but is also found in many other secreted eukaryotic proteins with variable architecture and biological function. It is responsible for the incorporation of ZP3 and other subunits into the ZP and consists of two domains, ZP-N and ZP-C, that are separated by a protease-sensitive linker. Whereas ZP-N is thought to constitute a basic building block of ZP filaments, ZP-C may mediate the specificity of interaction between subunits. These processes are controlled by an external hydrophobic patch (EHP) contained within the C-terminal propeptide of ZP component precursors and an internal hydrophobic patch (IHP) inside the ZP module.

This superfamily entry represents the ZP-C domain.

DOI:10.1038/nature07599,DOI:10.1016/j.cell.2010.09.041, INTERPRO:IPR001507