Investigation of the structural and conformational preferences of ribosome-bound nascent chains using NMR paramagnetic relaxation enhancement measurements (360G-Wellcome-211900_Z_18_Z)
Co-translational folding is best studied by providing high-resolution structural descriptions of nascent polypeptides (NCs) as they emerge from the ribosome. This is achieved by producing snapshots of the process using ribosome-associated-nascent chains(RNCs) and developing 3D structural models by combining NMR spectroscopy as experimental restraints within MD simulations. The emerging NC is a dynamic entity that searches conformational space in its quest for acquiring its correct structure; it undergoes both transient interactions with itself and the external surface of its ribosome. This Scholarship aims to develop novel distance-based, PRE (paramagnetic-relaxation-enhancement) NMR measurements of RNCs to evaluate these transient processes. Over 8 weeks, this project will enable us to develop strategies to selectively label RNCs with the MTSL "spin-labels" at a single cysteine site, by adapting well-established RNC technology. We will study two RNCs "snapshots" which capture early folding transition for an immunoglobulin protein. We will characterise the structural properties of the modified RNCs using 2D NMR spectroscopy, and quantitate possible transient interactions/compaction events by collecting PRE measurements. We will also initiate MD simulations with the new experimental restraints that have been acquired. These approaches will advance our current 3D structural models to dissect further molecular details of co-translational protein folding.
£0 31 May 2018