PDZ domain of neuronal nitric oxide synthase (nNOS), and related domains
PDZ (PSD-95 (Postsynaptic density protein 95), Dlg (Discs large protein), and ZO-1 (Zonula occludens-1)) domain 1 of nNOS, and related domains. nNOS produces a key signaling molecule, nitric oxide (NO), which has diverse functions throughout the body and acts as a neurotransmitter and intracellular signaling molecule in the central and peripheral nervous system. nNOS is concentrated at synaptic junctions in the brain and motor endplates in skeletal muscle. The PDZ domain of neuronal nitric oxide synthase (nNOS) interacts with the PDZ domain of alpha1-syntrophin (in muscle cells) and with the second PDZ domain of Disks large homolog 4 (Dlg4, also known as PSD-95), and nitric oxide synthase 1 adaptor protein NOS1AP in neurons. Dlg4 binds NMDA receptors, and nNOS, forming a complex in neurons. NOS1AP competes with Dgl4 for the nNOS PDZ domain and prevents the coupling of nNos activation with NMDA receptor-mediated calcium influx. 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 nNOS-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
Structure:1B8Q: PDZ domain of Rattus norvegicus nNOS binds MelR peptide (VVKVDSV, a synthetic peptide which corresponds to an identical sequence in the C-terminal domain of the melatonin receptor); contacts at 4A
Jiyao W et al.(2023). "The conserved domain database in 2023.",