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Published on: December 30, 2016
Crystal structure of a PDZ domain
J H Morais Cabral1, C Petosa, M J Sutcliffe
1Department of Biochemistry, University of Leicester, UK.
Nature
|August 15, 1996
Summary
PDZ domains are protein-recognition modules involved in cell signaling. Researchers determined the crystal structure of a human PDZ domain, revealing a groove and pocket likely involved in binding C-terminal peptides.
Area of Science:
- Molecular Biology
- Structural Biology
- Biochemistry
Background:
- PDZ domains are protein-recognition modules crucial for protein interactions in cellular signaling pathways.
- These domains are implicated in receptor clustering and linking receptors to effector enzymes, playing roles in ion-channel function.
- Some PDZ domains specifically recognize C-terminal motifs (S/TXV) on other proteins, while others engage in homotypic dimerization.
Purpose of the Study:
- To elucidate the three-dimensional structure of the third PDZ domain from the human homologue of Drosophila discs-large (DlgA).
- To identify potential functional sites within the PDZ domain structure responsible for protein-peptide interactions.
Main Methods:
- X-ray crystallography was employed to determine the high-resolution structure of the DlgA PDZ domain.
- Structural analysis focused on identifying conserved features and potential binding interfaces.
Main Results:
- The crystal structure reveals a canonical PDZ domain fold consisting of a five-stranded antiparallel beta-barrel and three flanking alpha-helices.
- A prominent groove on the domain surface leads to a conserved hydrophobic pocket and a buried arginine residue.
- This structural arrangement suggests a specific binding site for C-terminal peptides.
Conclusions:
- The determined structure provides a molecular basis for understanding PDZ domain-mediated protein recognition.
- The identified groove, hydrophobic pocket, and arginine residue are proposed as the key interaction site for C-terminal peptide binding.
- This structural insight aids in comprehending the role of PDZ domains in protein complex assembly and cellular signaling.
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