Two‐state conformational equilibrium in the Par‐4 leucine zipper domain |
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| Authors: | Martin Schwalbe Kaushik Dutta David S Libich Hariprasad Venugopal Jolyon K Claridge David A Gell Joel P Mackay Patrick J B Edwards Steven M Pascal |
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| Institution: | 1. Centre for Structural Biology, Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand;2. New York Structural Biology Centre, 89 Convent Avenue, New York, New York 10027;3. School of Molecular and Microbial Biosciences, University of Sydney, New South Wales 2006, Australia |
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| Abstract: | Prostate apoptosis response factor‐4 (Par‐4) is a pro‐apoptotic and tumor‐suppressive protein. A highly conserved heptad repeat sequence at the Par‐4 C‐terminus suggests the presence of a leucine zipper (LZ). This C‐terminal region is essential for Par‐4 self‐association and interaction with various effector proteins. We have used nuclear magnetic resonance (NMR) spectroscopy to fully assign the chemical shift resonances of a peptide comprising the LZ domain of Par‐4 at neutral pH. Further, we have investigated the properties of the Par‐4 LZ domain and two point mutants under a variety of conditions using NMR, circular dichroism (CD), light scattering, and bioinformatics. Results indicate an environment‐dependent conformational equilibrium between a partially ordered monomer (POM) and a predominantly coiled coil dimer (CCD). The combination of techniques used allows the time scales of the equilibrium to be probed and also helps to identify features of the amino acid sequence that may influence the equilibrium. Proteins 2010. © 2010 Wiley‐Liss, Inc. |
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| Keywords: | prostate apoptosis response factor 4 leucine zipper circular dichroism solution NMR spectroscopy |
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