8RKI

Molecular basis of ZP3/ZP1 heteropolymerization: crystal structure of a native vertebrate egg coat filament fragment

Summary for 8RKI

• Entry DOI: 10.2210/pdb8rki/pdb
• Related: 3NK4 5BUP 5OSQ 6TQK 8BQU
• Descriptor: Zona pellucida sperm-binding protein 3, Choriogenin H, beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, ... (5 entities in total)
• Functional Keywords: cell adhesion, fertilization, egg-sperm interaction, gamete recognition, sperm receptor, extracellular matrix, egg coat, zona pellucida, vitelline envelope, fish chorion, glycoprotein, n-glycan, structural protein, zp module, zp-n domain, zp-c domain, trefoil domain, medaka, japanese rice fish
• Biological source: Oryzias latipes (Japanese medaka); More
• Total number of polymer chains: 3
• Total formula weight: 72762.30

Authors

Wiseman, B.,Zamora-Caballero, S.,de Sanctis, D.,Yasumasu, S.,Jovine, L. (deposition date: 2023-12-25, release date: 2024-03-13, Last modification date: 2024-10-09)

Primary citation

Nishio, S.,Emori, C.,Wiseman, B.,Fahrenkamp, D.,Dioguardi, E.,Zamora-Caballero, S.,Bokhove, M.,Han, L.,Stsiapanava, A.,Algarra, B.,Lu, Y.,Kodani, M.,Bainbridge, R.E.,Komondor, K.M.,Carlson, A.E.,Landreh, M.,de Sanctis, D.,Yasumasu, S.,Ikawa, M.,Jovine, L.
ZP2 cleavage blocks polyspermy by modulating the architecture of the egg coat.
Cell, 187:1440-1459.e24, 2024

PubMed Abstract: Following the fertilization of an egg by a single sperm, the egg coat or zona pellucida (ZP) hardens and polyspermy is irreversibly blocked. These events are associated with the cleavage of the N-terminal region (NTR) of glycoprotein ZP2, a major subunit of ZP filaments. ZP2 processing is thought to inactivate sperm binding to the ZP, but its molecular consequences and connection with ZP hardening are unknown. Biochemical and structural studies show that cleavage of ZP2 triggers its oligomerization. Moreover, the structure of a native vertebrate egg coat filament, combined with AlphaFold predictions of human ZP polymers, reveals that two protofilaments consisting of type I (ZP3) and type II (ZP1/ZP2/ZP4) components interlock into a left-handed double helix from which the NTRs of type II subunits protrude. Together, these data suggest that oligomerization of cleaved ZP2 NTRs extensively cross-links ZP filaments, rigidifying the egg coat and making it physically impenetrable to sperm.

PubMed: 38490181
DOI: 10.1016/j.cell.2024.02.013

Experimental method

X-RAY DIFFRACTION (4.2 Å)