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Publication Abstract from PubMed

In proteins where conformational changes are functionally important, the number of accessible states and their dynamics are often difficult to establish. Here we describe a novel (19)F-NMR spectroscopy approach to probe dynamics of large membrane proteins. We labeled a glutamate transporter homolog with a (19)F probe via cysteine chemistry and with a Ni(2+) ion via chelation by a di-histidine motif. We used distance-dependent enhancement of the longitudinal relaxation of (19)F nuclei by the paramagnetic metal to assign the observed resonances. We identified one inward- and two outward-facing states of the transporter, in which the substrate-binding site is near the extracellular and intracellular solutions, respectively. We then resolved the structure of the unanticipated second outward-facing state by cryo-EM. Finally, we showed that the rates of the conformational exchange are accessible from measurements of the metal-enhanced longitudinal relaxation of (19)F nuclei.

Use of paramagnetic (19)F NMR to monitor domain movement in a glutamate transporter homolog.,Huang Y, Wang X, Lv G, Razavi AM, Huysmans GHM, Weinstein H, Bracken C, Eliezer D, Boudker O Nat Chem Biol. 2020 Sep;16(9):1006-1012. doi: 10.1038/s41589-020-0561-6. Epub, 2020 Jun 8. PMID:32514183^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.