ESEEM Reveals Bound Substrate Histidine in the ABC Transporter HisQMP2
| Autor: | Johanna Heuveling, Erwin Schneider, Nikolay Isaev, Heinz-Jürgen Steinhoff, Nikita V. Ivanisenko |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Chemistry
ATP-binding cassette transporter Site-directed spin labeling 010402 general chemistry 01 natural sciences Atomic and Molecular Physics and Optics 030218 nuclear medicine & medical imaging 0104 chemical sciences 03 medical and health sciences Crystallography 0302 clinical medicine Homology modeling Binding site Spin label Spin (physics) Conformational isomerism Histidine |
| Zdroj: | Applied Magnetic Resonance. 50:883-893 |
| ISSN: | 1613-7507 0937-9347 |
| DOI: | 10.1007/s00723-019-01114-y |
| Popis: | Localization of substrates in membrane proteins is an important but challenging task. In this paper, we show that deuterium electron spin echo envelope modulation spectroscopy (2H ESEEM) combined with site-directed spin labeling is a powerful tool to localize the substrate, histidine-d5, in the ABC transporter HisQMP2. Based on a homology model and spin label rotamer analyses, we calculated 2H ESEEM spectra for eight possible labeling positions close to the putative substrate-binding site. Experimental 2H ESEEM spectra were determined with spin labels bound either at position 169 of HisM, for which a detectable 2H ESEEM signal was calculated, or with a spin label bound at position 54 of HisQ as a negative control. The agreement between the calculated and experimental ESEEM spectra provides strong evidence for the histidine located in a binding site primarily liganded by residues of HisM as proposed by the homology model. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full text from SpringerLink