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Peptide Binding Properties of the Three PDZ Domains of Bazooka (Drosophila Par-3)
- Source :
- PLoS ONE, PLoS ONE, Vol 9, Iss 1, p e86412 (2014)
- Publication Year :
- 2014
- Publisher :
- Public Library of Science (PLoS), 2014.
-
Abstract
- The Par complex is a conserved cell polarity regulator. Bazooka/Par-3 is scaffold for the complex and contains three PDZ domains in tandem. PDZ domains can act singly or synergistically to bind the C-termini of interacting proteins. Sequence comparisons among Drosophila Baz and its human and C. elegans Par-3 counterparts indicate a divergence of the peptide binding pocket of PDZ1 and greater conservation for the pockets of PDZ2 and PDZ3. However, it is unclear whether the domains from different species share peptide binding preferences, or if their tandem organization affects their peptide binding properties. To investigate these questions, we first used phage display screens to identify unique peptide binding profiles for each single PDZ domain of Baz. Comparisons with published phage display screens indicate that Baz and C. elegans PDZ2 bind to similar peptides, and that the peptide binding preferences of Baz PDZ3 are more similar to C. elegans versus human PDZ3. Next we quantified the peptide binding preferences of each Baz PDZ domain using single identified peptides in surface plasmon resonance assays. In these direct binding studies, each peptide had a binding preference for a single PDZ domain (although the peptide binding of PDZ2 was weakest and the least specific). PDZ1 and PDZ3 bound their peptides with dissociation constants in the nM range, whereas PDZ2-peptide binding was in the µM range. To test whether tandem PDZ domain organization affects peptide binding, we examined a fusion protein containing all three PDZ domains and their normal linker regions. The binding strengths of the PDZ-specific peptides to single PDZ domains and to the PDZ domain tandem were indistinguishable. Thus, the peptide binding pockets of each PDZ domain in Baz are not obviously affected by the presence of neighbouring PDZ domains, but act as isolated modules with specific in vitro peptide binding preferences.
- Subjects :
- Protein Structure
Phage display
Amino Acid Motifs
Molecular Sequence Data
Protein domain
PDZ domain
lcsh:Medicine
PDZ Domains
Peptide binding
Peptide
Plasma protein binding
Biology
Biochemistry
Model Organisms
Animals
Drosophila Proteins
Humans
Position-Specific Scoring Matrices
Amino Acid Sequence
Biomacromolecule-Ligand Interactions
lcsh:Science
Protein Interactions
Peptide sequence
Conserved Sequence
chemistry.chemical_classification
Multidisciplinary
Drosophila Melanogaster
lcsh:R
Intracellular Signaling Peptides and Proteins
Proteins
Animal Models
Molecular biology
Fusion protein
Recombinant Proteins
Regulatory Proteins
chemistry
Biophysics
lcsh:Q
Drosophila
Structural Proteins
Peptides
Sequence Alignment
Research Article
Protein Binding
Subjects
Details
- ISSN :
- 19326203
- Volume :
- 9
- Database :
- OpenAIRE
- Journal :
- PLoS ONE
- Accession number :
- edsair.doi.dedup.....8a48572fd5fe2ce879864b1a4404a576