National Institutes of Health/National Human Genome Research Institute (NIH/NHGRI)
R37NS085318
米国
National Institutes of Health/National Human Genome Research Institute (NIH/NHGRI)
R01NS064357
米国
引用
ジャーナル: Nat Chem Biol / 年: 2020 タイトル: Use of paramagnetic F NMR to monitor domain movement in a glutamate transporter homolog. 著者: Yun Huang / Xiaoyu Wang / Guohua Lv / Asghar M Razavi / Gerard H M Huysmans / Harel Weinstein / Clay Bracken / David Eliezer / Olga Boudker / 要旨: 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 F-NMR spectroscopy ...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 F-NMR spectroscopy approach to probe dynamics of large membrane proteins. We labeled a glutamate transporter homolog with a F probe via cysteine chemistry and with a Ni ion via chelation by a di-histidine motif. We used distance-dependent enhancement of the longitudinal relaxation of 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 F nuclei.