Movie
Controller
Structure viewers
About Yorodumi Papers
+Search query
-Structure paper
| Title | Cryo-EM structure and dynamics of the green-light absorbing proteorhodopsin. |
|---|---|
| Journal, issue, pages | Nat Commun, Vol. 12, Issue 1, Page 4107, Year 2021 |
| Publish date | Jul 5, 2021 |
 Authors | Stephan Hirschi / David Kalbermatter / Zöhre Ucurum / Thomas Lemmin / Dimitrios Fotiadis /  |
| PubMed Abstract | The green-light absorbing proteorhodopsin (GPR) is the archetype of bacterial light-driven proton pumps. Here, we present the 2.9 Å cryo-EM structure of pentameric GPR, resolving important ...The green-light absorbing proteorhodopsin (GPR) is the archetype of bacterial light-driven proton pumps. Here, we present the 2.9 Å cryo-EM structure of pentameric GPR, resolving important residues of the proton translocation pathway and the oligomerization interface. Superposition with the structure of a close GPR homolog and molecular dynamics simulations reveal conformational variations, which regulate the solvent access to the intra- and extracellular half channels harbouring the primary proton donor E109 and the proposed proton release group E143. We provide a mechanism for the structural rearrangements allowing hydration of the intracellular half channel, which are triggered by changing the protonation state of E109. Functional characterization of selected mutants demonstrates the importance of the molecular organization around E109 and E143 for GPR activity. Furthermore, we present evidence that helices involved in the stabilization of the protomer interfaces serve as scaffolds for facilitating the motion of the other helices. Combined with the more constrained dynamics of the pentamer compared to the monomer, these observations illustrate the previously demonstrated functional significance of GPR oligomerization. Overall, this work provides molecular insights into the structure, dynamics and function of the proteorhodopsin family that will benefit the large scientific community employing GPR as a model protein. |
 External links | Nat Commun / PubMed:34226545 / PubMed Central |
| Methods | EM (single particle) |
| Resolution | 2.93 Å |
| Structure data | EMDB-11955, PDB-7b03: |
| Chemicals |  ChemComp-RET: |
| Source |
|
 Keywords |  PROTON TRANSPORT / Light-driven proton pump / microbial rhodopsin / retinal |
uncultured gammaproteobacteria bacterium (environmental samples)