PDZ domain of tamalin, cytohesin-1-interacting protein (CYTIP), and related domains
PDZ (PSD-95 (Postsynaptic density protein 95), Dlg (Discs large protein), and ZO-1 (Zonula occludens-1)) domain of tamalin, cytohesin-1-interacting protein, and related domains. Tamalin (trafficking regulator and scaffold protein tamalin, also known as general receptor for phosphoinositides 1-associated scaffold protein, GRASP) functions to link receptors, including group 1 metabotropic glutamate receptors (mGluRs), to neuronal proteins. The tamalin PDZ domain binds the C-terminal domains of group I mGluRs; it also binds potassium/sodium hyperpolarization-activated cyclic nucleotide-gated channel 2 (HCN2), neurotrophin-3 (NT3) TrkCT1-truncated receptor, SAP90/PSD-95-associated protein, and tamalin itself. CYTIP (cytohesin-1-interacting protein, also known as Pleckstrin homology Sec7 and coiled-coil domain-binding protein) sequesters cytohesin-1 in the cytoplasm, limiting its interaction with beta2 integrins; cytohesin-1 binds the CYTIP coiled coil domain. The CYTIP PDZ domain can bind the C-terminal peptide of protocadherin alpha-1 (PCDHA1), indicating a possible interaction between the two. 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 tamalin-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
Structure:2EGK: PDZ domain of Rattus norvegicus tamalin binds the C-terminal (ESQL) extension of an adjacent tamalin PDZ domain structure, contacts at 4A
Comment:PDZ domains specifically recognize and bind to short C-terminal peptide motifs, but can also recognize internal peptide motifs and certain lipids