Conformational Dynamics of apo-GlnBP Revealed by Experimental and Computational Analysis

The glutamine binding protein (GlnBP) binds l-glutamine and cooperates with its cognate transporters during glutamine uptake. Crystal structure analysis has revealed an open and a closed conformation for apo- and holo-GlnBP, respectively. However, the detailed conformational dynamics have remained unclear. Herein, we combined NMR spectroscopy, MD simulations, and single-molecule FRET techniques to decipher the conformational dynamics of apo-GlnBP. The NMR residual dipolar couplings of apo-GlnBP were in good agreement with a MD-derived structure ensemble consisting of four metastable states. The open and closed conformations are the two major states. This four-state model was further validated by smFRET experiments and suggests the conformational selection mechanism in ligand recognition of GlnBP. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Citation

Feng Y, Zhang L, Wu S, Liu Z, Gao X, et al. (2016) Conformational Dynamics of apo-GlnBP Revealed by Experimental and Computational Analysis. Angewandte Chemie International Edition 55: 13990–13994. Available: http://dx.doi.org/10.1002/anie.201606613.

Sponsors

This work was supported by the National Major Basic Research Program of China (2016YFA0501702), the National Science Foundation of China (21473034, 21273188), and the Specialized Research Fund for the Doctoral Program of Higher Education (20130071140004). X.H. acknowledges the Hong Kong Research Grants Council (M-HKUST601/13, 609813, 16302214, 16304215, and HKUST C6009-15G). X.G. acknowledges funding from King Abdullah University of Science and Technology (KAUST). We thank Dr. Charles D. Schwieters for insightful discussions and the facility team members for their help with NMR experiments at the National Center for Protein Science Shanghai (NCPSS). This research made use of the computer cluster resources at KAUST.