PDZ (PSD-95 (Postsynaptic density protein 95), Dlg (Discs large protein), and ZO-1 (Zonula occludens-1)) domain of Lin-7 (also known as LIN-7 or LIN7), and related domains. Lin-7 targets and organize protein complexes to epithelial and synaptic plasma membranes. There are three mammalian Lin-7 homologs: Lin-7A (protein lin-7 homolog A, also known as mammalian lin-seven protein 1 (MALS-1), vertebrate lin-7 homolog 1 (Veli-1), tax interaction protein 33); Lin-7B (also known as MALS-2, Veli-2); and Lin-7C (also known as MALS-3, Veli-3). Lin-7 is involved in localization of the Let-23 growth factor receptor to the basolateral membrane of epithelial cells, in tight junction localization of insulin receptor substrate p53 (IRSp53), in retaining gamma-aminobutyric (GABA) transporter (BGT-1) at the basolateral surface of epithelial cells, and in regulating recruitment of neurotransmitter receptors to the postsynaptic density (PSD). The Lin7 PDZ domain binds Let-23, BGT and beta-catenin, and NMDA (N-methyl-D-aspartate) receptor NR2B. Lin-7 also binds to the PDZ binding motif located in the C-terminal tail of Rhotekin, an effector protein for small GTPase Rho. 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 Lin-7-like family 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
Jiyao W et al.(2023). "The conserved domain database in 2023.",