This administrative supplement proposal is for a custom-built 800 MHz solid state NMR (SSNMR) probe that will allow detection of 1H, 19F, 31P, 13C and 15N nuclei. Until now, such probes have only been available for wide bore magnets at a maximum frequency of 600 MHz. Now, Phoenix NMR has developed a standard bore magic-angle spinning probe with a 1.6 mm rotor capable of spinning up to 40 kHz, with the full range of tuning configurations to enable molecular structure determination at 800 MHz. The radio frequency solenoid coil can be tuned simultaneously to three or four frequencies, including all the triple resonance combinations required for standard applications (HPC, HCN, HPN) as well as novel, quadruple resonance configurations involving 19F, such as HFPC, HFCN, and HFPN. The Phoenix probe is the only standard bore design available that supports 1H decoupling while observing 19F and two other nuclei. We anticipate the combined improvements in resolution and sensitivity at 800 MHz will enable complete assignments of biomolecules and complexes of molecular weight 20 to 50 kDa, as well as studies of dynamics utilizing dipolar order parameter and relaxation methods. The probe will be used for projects in the Butcher and Henzler-Wildman laboratories and will be placed in the National Magnetic Resonance Facility at Madison (NMRFAM) at UW-Madison, which has recently recruited SSNMR expert Prof. Chad Rienstra (formerly U. Illinois). Thus, the probe will support at least 3 groups from within UW- Madison and will also be accessible to an extensive outside user base. The Butcher lab will use the probe to investigate poly-UG RNA and its association with the protein TDP-43. Due to the highly repetitive RNA sequence, these studies will make use of site-specific 2? fluoro groups on the RNA. A 1.0 crystal structure of the free RNA has been solved and NMR assignments have been made, which will facilitate structure determination of the complex by SSNMR. The Henzler-Wildman lab will use the probe to study how the bacterial EmrE multi-drug transporter and its interaction with fluorinated substrates. HN-resolved 1H-19F REDOR experiments have been performed that demonstrate the feasibility of the project.
The National Magnetic Resonance Facility at Madison (NMRFAM) is a resource center for biomolecular nuclear magnetic resonance (NMR) spectroscopy, serving a wide user base from across the US. The new generation solid-state NMR (SSNMR) probe described in this proposal would allow our 800 MHz instrument to be used for a wide variety of novel SSNMR applications with signal to noise and resolution that were not previously achievable. The probe will be used for structure determination of RNA-protein complexes in the Butcher Laboratory, investigating membrane protein-drug interactions in the Henzler-Wildman laboratory, and will generally be available to other users both external and internal (Rienstra).
| Robinson, Anne E; Henderson, Jeffrey P; Henzler-Wildman, Katherine A (2018) A mass spectrometry based transport assay for studying EmrE transport of unlabeled substrates. Anal Biochem 549:130-135 |
| Thomas, Nathan E; Wu, Chao; Morrison, Emma A et al. (2018) The C terminus of the bacterial multidrug transporter EmrE couples drug binding to proton release. J Biol Chem 293:19137-19147 |
| Robinson, Anne E; Thomas, Nathan E; Morrison, Emma A et al. (2017) New free-exchange model of EmrE transport. Proc Natl Acad Sci U S A 114:E10083-E10091 |
| Morrison, Emma A; Robinson, Anne E; Liu, Yongjia et al. (2015) Asymmetric protonation of EmrE. J Gen Physiol 146:445-61 |
| Morrison, Emma A; Henzler-Wildman, Katherine A (2014) Transported substrate determines exchange rate in the multidrug resistance transporter EmrE. J Biol Chem 289:6825-36 |
| Dutta, Supratik; Morrison, Emma A; Henzler-Wildman, Katherine A (2014) EmrE dimerization depends on membrane environment. Biochim Biophys Acta 1838:1817-22 |
| Dutta, Supratik; Morrison, Emma A; Henzler-Wildman, Katherine A (2014) Blocking dynamics of the SMR transporter EmrE impairs efflux activity. Biophys J 107:613-620 |
| Morrison, Emma A; DeKoster, Gregory T; Dutta, Supratik et al. (2012) Antiparallel EmrE exports drugs by exchanging between asymmetric structures. Nature 481:45-50 |
| Morrison, Emma A; Henzler-Wildman, Katherine A (2012) Reconstitution of integral membrane proteins into isotropic bicelles with improved sample stability and expanded lipid composition profile. Biochim Biophys Acta 1818:814-20 |
| Henzler-Wildman, Katherine (2012) Analyzing conformational changes in the transport cycle of EmrE. Curr Opin Struct Biol 22:38-43 |
