5f67
An exquisitely specific PDZ/target recognition revealed by the structure of INAD PDZ3 in complex with TRP channel tail
Structural highlights
FunctionINAD_DROME Involved in the negative feedback regulation of the light-activated signaling cascade in photoreceptors through a calcium-mediated process. Interacts with tetrapeptide ligand located in C-terminal sequence of 3 key components of the visual cascade, tethering them and forming a macromolecular signaling phototransduction complex.[1] [2] Publication Abstract from PubMedThe vast majority of PDZ domains are known to bind to a few C-terminal tail residues of target proteins with modest binding affinities and specificities. Such promiscuous PDZ/target interactions are not compatible with highly specific physiological functions of PDZ domain proteins and their targets. Here, we report an unexpected PDZ/target binding occurring between the scaffold protein inactivation no afterpotential D (INAD) and transient receptor potential (TRP) channel in Drosophila photoreceptors. The C-terminal 15 residues of TRP are required for the specific interaction with INAD PDZ3. The INAD PDZ3/TRP peptide complex structure reveals that only the extreme C-terminal Leu of TRP binds to the canonical alphaB/betaB groove of INAD PDZ3. The rest of the TRP peptide, by forming a beta hairpin structure, binds to a surface away from the alphaB/betaB groove of PDZ3 and contributes to the majority of the binding energy. Thus, the INAD PDZ3/TRP channel interaction is exquisitely specific and represents a new mode of PDZ/target recognitions. An Exquisitely Specific PDZ/Target Recognition Revealed by the Structure of INAD PDZ3 in Complex with TRP Channel Tail.,Ye F, Liu W, Shang Y, Zhang M Structure. 2016 Jan 27. pii: S0969-2126(16)00006-X. doi:, 10.1016/j.str.2015.12.013. PMID:26853938[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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