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Open data
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Basic information
Entry | Database: PDB / ID: 7kzx | ||||||
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Title | Cryo-EM structure of YiiP-Fab complex in Apo state | ||||||
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Function / homology | ![]() zinc efflux active transmembrane transporter activity / cadmium ion transmembrane transporter activity / ferrous iron transmembrane transporter activity / intracellular zinc ion homeostasis / ![]() ![]() Similarity search - Function | ||||||
Biological species | ![]() ![]() ![]() ![]() | ||||||
Method | ![]() ![]() ![]() | ||||||
![]() | Lopez-Redondo, M.L. / Fan, S. / Koide, A. / Koide, S. / Beckstein, O. / Stokes, D.L. | ||||||
Funding support | ![]()
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![]() | ![]() Title: Zinc binding alters the conformational dynamics and drives the transport cycle of the cation diffusion facilitator YiiP. Authors: Maria Lopez-Redondo / Shujie Fan / Akiko Koide / Shohei Koide / Oliver Beckstein / David L Stokes / ![]() Abstract: YiiP is a secondary transporter that couples Zn2+ transport to the proton motive force. Structural studies of YiiP from prokaryotes and Znt8 from humans have revealed three different Zn2+ sites and a ...YiiP is a secondary transporter that couples Zn2+ transport to the proton motive force. Structural studies of YiiP from prokaryotes and Znt8 from humans have revealed three different Zn2+ sites and a conserved homodimeric architecture. These structures define the inward-facing and outward-facing states that characterize the archetypal alternating access mechanism of transport. To study the effects of Zn2+ binding on the conformational transition, we use cryo-EM together with molecular dynamics simulation to compare structures of YiiP from Shewanella oneidensis in the presence and absence of Zn2+. To enable single-particle cryo-EM, we used a phage-display library to develop a Fab antibody fragment with high affinity for YiiP, thus producing a YiiP/Fab complex. To perform MD simulations, we developed a nonbonded dummy model for Zn2+ and validated its performance with known Zn2+-binding proteins. Using these tools, we find that, in the presence of Zn2+, YiiP adopts an inward-facing conformation consistent with that previously seen in tubular crystals. After removal of Zn2+ with high-affinity chelators, YiiP exhibits enhanced flexibility and adopts a novel conformation that appears to be intermediate between inward-facing and outward-facing states. This conformation involves closure of a hydrophobic gate that has been postulated to control access to the primary transport site. Comparison of several independent cryo-EM maps suggests that the transition from the inward-facing state is controlled by occupancy of a secondary Zn2+ site at the cytoplasmic membrane interface. This work enhances our understanding of individual Zn2+ binding sites and their role in the conformational dynamics that govern the transport cycle. | ||||||
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Structure visualization
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Structure viewer | Molecule: ![]() ![]() |
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Downloads & links
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Download
PDBx/mmCIF format | ![]() | 239.4 KB | Display | ![]() |
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PDB format | ![]() | 194.3 KB | Display | ![]() |
PDBx/mmJSON format | ![]() | Tree view | ![]() | |
Others | ![]() |
-Validation report
Arichive directory | ![]() ![]() | HTTPS FTP |
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-Related structure data
Related structure data | ![]() 23092MC ![]() 7kzzC M: map data used to model this data C: citing same article ( |
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Similar structure data |
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Links
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Assembly
Deposited unit | ![]()
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Components
#1: Protein | Mass: 32485.211 Da / Num. of mol.: 2 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() ![]() ![]() ![]() #2: Antibody | Mass: 23580.242 Da / Num. of mol.: 2 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() ![]() ![]() ![]() #3: Antibody | Mass: 25406.352 Da / Num. of mol.: 2 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() ![]() ![]() ![]() |
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-Experimental details
-Experiment
Experiment | Method: ![]() |
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EM experiment | Aggregation state: PARTICLE / 3D reconstruction method: ![]() |
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Sample preparation
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Molecular weight |
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Source (recombinant) |
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Buffer solution | pH: 7.5 | |||||||||||||||||||||||||||||||||||
Buffer component |
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Specimen | Conc.: 3 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied![]() ![]() Details: YiiP-Fab2R complex purified through SEC with DM, the same day as grid freezing. Main peak fraction was used for freezing. | |||||||||||||||||||||||||||||||||||
Specimen support | Grid material: GOLD / Grid mesh size: 300 divisions/in. / Grid type: UltrAuFoil R1.2/1.3 | |||||||||||||||||||||||||||||||||||
Vitrification![]() | Instrument: FEI VITROBOT MARK IV / Cryogen name: ETHANE / Humidity: 100 % / Chamber temperature: 277 K Details: 3ul of protein mixture applied to grid. Blot time 4 seconds, blot force 0. |
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Electron microscopy imaging
Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company |
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Microscopy | Model: FEI TITAN KRIOS |
Electron gun | Electron source![]() ![]() |
Electron lens | Mode: BRIGHT FIELD![]() ![]() |
Specimen holder | Cryogen: NITROGEN / Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER / Temperature (max): 77 K / Temperature (min): 77 K |
Image recording | Average exposure time: 10 sec. / Electron dose: 65 e/Å2 / Film or detector model: GATAN K2 QUANTUM (4k x 4k) / Num. of grids imaged: 1 / Num. of real images: 1945 |
EM imaging optics | Energyfilter name![]() |
Image scans | Sampling size: 14 µm / Width: 3710 / Height: 3838 / Movie frames/image: 50 |
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Processing
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EM software |
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CTF correction![]() | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | |||||||||||||||||||||||||||||||||||||||||||||
Particle selection | Num. of particles selected: 848576 | |||||||||||||||||||||||||||||||||||||||||||||
Symmetry | Point symmetry![]() | |||||||||||||||||||||||||||||||||||||||||||||
3D reconstruction![]() | Resolution: 4 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 140565 / Algorithm: FOURIER SPACE / Num. of class averages: 2 / Symmetry type: POINT | |||||||||||||||||||||||||||||||||||||||||||||
Atomic model building | B value: 101 / Protocol: BACKBONE TRACE / Space: REAL / Target criteria: cross-correlation | |||||||||||||||||||||||||||||||||||||||||||||
Atomic model building | PDB-ID: 5VRF | |||||||||||||||||||||||||||||||||||||||||||||
Refinement | Cross valid method: NONE Stereochemistry target values: GeoStd + Monomer Library + CDL v1.2 | |||||||||||||||||||||||||||||||||||||||||||||
Displacement parameters | Biso mean: 101.64 Å2 | |||||||||||||||||||||||||||||||||||||||||||||
Refine LS restraints |
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