PDZ (PSD-95 (Postsynaptic density protein 95), Dlg (Discs large protein), and ZO-1 (Zonula occludens-1)) domain of syntrophins (including alpha-1-syntrophin, beta-1-syntrophin, beta-2-syntrophin, gamma-1-syntrophin, and gamma-2-syntrophin), and related domains. Syntrophins play a role in recruiting various signaling molecules into signaling complexes and help provide appropriate spatiotemporal regulation of signaling pathways. They function in cytoskeletal organization and maintenance; as components of the dystrophin-glycoprotein complex (DGC), they help maintain structural integrity of skeletal muscle fibers. They link voltage-gated sodium channels to the actin cytoskeleton and the extracellular matrix, and control the localization and activity of the actin reorganizing proteins such as PI3K, PI(3,4)P2 and TAPP1. Through association with various cytoskeletal proteins within the cells, they are involved in processes such as regulation of focal adhesions, myogenesis, calcium homeostasis, and cell migration. They also have roles in synapse formation and in the organization of utrophin, acetylcholine receptor, and acetylcholinesterase at the neuromuscular synapse. 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 syntrophin-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:2PDZ: PDZ domain of Mus musculus syntrophin binds peptide GVKESLV; contacts at 4A
Comment:syntrophin PDZ domain binds peptide ligands with the consensus sequence -E-S/T-X-V-COOH
Jiyao W et al.(2023). "The conserved domain database in 2023.",