PDZ domain 2 of Zonula Occludens-1 (ZO-1), ZO-2 and ZO-3, and related domains; form domain-swapping dimers
PDZ (PSD-95 (Postsynaptic density protein 95), Dlg (Discs large protein), and ZO-1 (Zonula occludens-1)) domain 2 of ZO-1, -2, -3 and related domains. Zonula occludens proteins (ZO-1, ZO-2, ZO-3) are multi-PDZ domain proteins involved in the maintenance and biogenesis of multi-protein networks at the cytoplasmic surface of intercellular contacts in epithelial and endothelial cells. They have three N-terminal PDZ domains, PDZ1-3, followed by a Src homology-3 (SH3) domain and a guanylate kinase (GuK)-like domain. Among protein-protein interactions for all ZO proteins is the binding of the first PDZ domain (PDZ1) to the C-termini of claudins , and the homo- and hetero-dimerization of ZO-proteins via their second PDZ domain (PDZ2), which takes place by symmetrical domain swapping of the first two beta-strands of PDZ2. At the cell level, ZO-1 and ZO-2 are involved in polarity maintenance, gene transcription, cell proliferation, and tumor cell metastasis. PDZ domains usually bind in a sequence-specific manner to short peptide sequences located at the C-terminal end of their partner proteins (known as PDZ binding motifs). The PDZ superfamily includes canonical PDZ domains as well as those with circular permutations and domain swapping mediated by beta-strands. This ZO family PDZ2 domain is a canonical PDZ domain containing six beta-strands A-F and two alpha-helices (alpha-helix 1 and 2), arranged in the order: beta-strands A, B, C, alpha-helix 1, beta-strands D, E, alpha-helix 2 and beta-strand F.
Feature 1:peptide binding site [polypeptide binding site]
Evidence:
Comment:based on canonical PDZ domains with structure
Comment:PDZ domains specifically recognize and bind to short C-terminal peptide motifs, but can also recognize internal peptide motifs and certain lipids
Structure:3CYY: Homo sapiens ZO-1 PDZ2 homodimer binds connexin43 peptide; contacts at 4A
Comment:domain-swapped dimerization of ZO-1 PDZ2 generates specific and regulatory connexin43-binding sites
Comment:the canonical peptide-binding groove remains intact in both subunits of the PDZ2 dimer and is created by elements contributed from both monomers
Jiyao W et al.(2023). "The conserved domain database in 2023.",