PDZ domain 3 of human discs large homolog 1 (Dlg1), Dlg2, and Dlg4, Drosophila disc large (Dlg), and related domains
PDZ (PSD-95 (Postsynaptic density protein 95), Dlg (Discs large protein), and ZO-1 (Zonula occludens-1)) domain 3 of Drosophila Dlg1, human Dlg1, 2, and 4 and related domains. Dlg1 (also known as synapse-associated protein Dlg197; SAP-97), Dlg2 (also known as channel-associated protein of synapse-110; postsynaptic density protein 93, PSD-93), Dlg4 (also known as postsynaptic density protein 95, PSD-95; synapse-associated protein 90, SAP-90) each have 3 PDZ domains and belong to the membrane-associated guanylate kinase family. Dlg1 regulates antigen receptor signaling and cell polarity in lymphocytes, B-cell proliferation and antibody production, and TGFalpha bioavailability; its PDZ3 domain binds pro-TGFalpha, and its PDZ2 domain binds the TACE metalloprotease responsible for cleaving pro-TGFalpha to a soluble form. Dlg2 is involved in N-methyl-D-aspartate (NMDA) receptor signaling, regulating surface expression of NMDA receptors in dorsal horn neurons of the spinal cord; it interacts with NMDA receptor subunits and with Shaker-type K+ channel subunits to cluster into a channel complex. The Dlg4 PDZ1 domain binds NMDA receptors, and its PDZ2 domain binds neuronal nitric oxide synthase (nNOS), forming a complex in neurons. The Drosophila Scribble complex (Scribble, Dlg, and lethal giant larvae) plays a role in apico-basal cell polarity, and in other forms of polarity, including regulation of the actin cytoskeleton, cell signaling and vesicular trafficking, and in tumor development; postsynaptic targeting of Drosophila DLG requires interactions mediated by the first two PDZ domains. 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 Dlg-like family PDZ3 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:1BE9: PDZ domain 3 of Rattus norvegicus Dlg4 binds C-terminal peptide derived from a PDZ3-interacting protein identified using a yeast two-hybrid screen; contacts at 4A
Jiyao W et al.(2023). "The conserved domain database in 2023.",