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-Structure paper
Title | Cryo-EM and MD infer water-mediated proton transport and autoinhibition mechanisms of V complex. |
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Journal, issue, pages | Sci Adv, Vol. 6, Issue 41, Year 2020 |
Publish date | Oct 7, 2020 |
Authors | Soung-Hun Roh / Mrinal Shekhar / Grigore Pintilie / Christophe Chipot / Stephan Wilkens / Abhishek Singharoy / Wah Chiu / |
PubMed Abstract | Rotary vacuolar adenosine triphosphatases (V-ATPases) drive transmembrane proton transport through a V proton channel subcomplex. Despite recent high-resolution structures of several rotary ATPases, ...Rotary vacuolar adenosine triphosphatases (V-ATPases) drive transmembrane proton transport through a V proton channel subcomplex. Despite recent high-resolution structures of several rotary ATPases, the dynamic mechanism of proton pumping remains elusive. Here, we determined a 2.7-Å cryo-electron microscopy (cryo-EM) structure of yeast V proton channel in nanodisc that reveals the location of ordered water molecules along the proton path, details of specific protein-lipid interactions, and the architecture of the membrane scaffold protein. Moreover, we uncover a state of V that shows the -ring rotated by ~14°. Molecular dynamics simulations demonstrate that the two rotary states are in thermal equilibrium and depict how the protonation state of essential glutamic acid residues couples water-mediated proton transfer with -ring rotation. Our cryo-EM models and simulations also rationalize a mechanism for inhibition of passive proton transport as observed for free V that is generated as a result of V-ATPase regulation by reversible disassembly in vivo. |
External links | Sci Adv / PubMed:33028525 / PubMed Central |
Methods | EM (single particle) |
Resolution | 2.7 - 3.6 Å |
Structure data | EMDB-30034, PDB-6m0r: EMDB-30035, PDB-6m0s: |
Chemicals | ChemComp-PEE: ChemComp-PPV: ChemComp-EYR: ChemComp-HOH: |
Source |
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Keywords | TRANSPORT PROTEIN / V-ATPase / Vo sub-complex / CryoEM / rotary motor |