Primary Citation of Related Structures:   3NK3, 3NK4
PubMed Abstract: 
ZP3, a major component of the zona pellucida (ZP) matrix coating mammalian eggs, is essential for fertilization by acting as sperm receptor. By retaining a propeptide that contains a polymerization-blocking external hydrophobic patch (EHP), we determined the crystal structure of an avian homolog of ZP3 at 2 ...
ZP3, a major component of the zona pellucida (ZP) matrix coating mammalian eggs, is essential for fertilization by acting as sperm receptor. By retaining a propeptide that contains a polymerization-blocking external hydrophobic patch (EHP), we determined the crystal structure of an avian homolog of ZP3 at 2.0 Å resolution. The structure unveils the fold of a complete ZP domain module in a homodimeric arrangement required for secretion and reveals how EHP prevents premature incorporation of ZP3 into the ZP. This suggests mechanisms underlying polymerization and how local structural differences, reflected by alternative disulfide patterns, control the specificity of ZP subunit interaction. Close relative positioning of a conserved O-glycan important for sperm binding and the hypervariable, positively selected C-terminal region of ZP3 suggests a concerted role in the regulation of species-restricted gamete recognition. Alternative conformations of the area around the O-glycan indicate how sperm binding could trigger downstream events via intramolecular signaling.
Related Citations: 
Mammalian Sperm-Egg Interaction: Identification of a Glycoprotein in Mouse Egg Zonae Pellucidae Possessing Receptor Activity for Sperm Bleil, J.D., Wassarman, P.M. (1980) Cell 20: 873
A Large Domain Common to Sperm Receptors (Zp2 and Zp3) and Tgf-Beta Type III Receptor Bork, P., Sander, C. (1992) FEBS Lett 300: 237
The chicken homologue of zona pellucida protein-3 is synthesized by granulosa cells Waclawek, M., Foisner, R., Nimpf, J., Schneider, W.J. (1998) Biol Reprod 59: 1230
A 42-kDa glycoprotein from chicken egg-envelope, an avian homolog of the ZPC family glycoproteins in mammalian Zona pellucida. Its first identification, cDNA cloning and granulosa cell-specific expression. Takeuchi, Y., Nishimura, K., Aoki, N., Adachi, T., Sato, C., Kitajima, K., Matsuda, T. (1999) Eur J Biochem 260: 736
The Zp Domain is a Conserved Module for Polymerization of Extracellular Proteins Jovine, L., Qi, H., Williams, Z., Litscher, E., Wassarman, P.M. (2002) Nat Cell Biol 4: 457
A Duplicated Motif Controls Assembly of Zona Pellucida Domain Proteins Jovine, L., Qi, H., Williams, Z., Litscher, E.S., Wassarman, P.M. (2004) Proc Natl Acad Sci U S A 101: 5922
Zona Pellucida Domain Proteins Jovine, L., Darie, C.C., Litscher, E.S., Wassarman, P.M. (2005) Annu Rev Biochem 74: 83
Crystal Structure of the Zp-N Domain of Zp3 Reveals the Core Fold of Animal Egg Coats Monne, M., Han, L., Schwend, T., Burendahl, S., Jovine, L. (2008) Nature 456: 653
Organizational Affiliation: 
Department of Biosciences and Nutrition, Center for Biosciences, Karolinska Institutet, Huddinge, Sweden.