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Open data
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Basic information
Entry | Database: PDB / ID: 8ypd | ||||||
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Title | Cryo-EM structure of the LH1 complex from Allochromatium tepidum | ||||||
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![]() | PHOTOSYNTHESIS / LH1 COMPLEX | ||||||
Function / homology | ![]() plasma membrane light-harvesting complex / bacteriochlorophyll binding / photosynthesis, light reaction / : / metal ion binding / plasma membrane Similarity search - Function | ||||||
Biological species | ![]() | ||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 2.78 Å | ||||||
![]() | Wang, G.-L. / Sun, S. / Yu, L.-J. | ||||||
Funding support | ![]()
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![]() | ![]() Title: Probing the Dual Role of Ca in the LH1-RC Complex by Constructing and Analyzing Ca-Bound and Ca-Free LH1 Complexes. Authors: Mei-Juan Zou / Shuai Sun / Guang-Lei Wang / Yi-Hao Yan / Wei Ji / Zheng-Yu Wang-Otomo / Michael T Madigan / Long-Jiang Yu / ![]() ![]() ![]() Abstract: The genome of the mildly thermophilic hot spring purple sulfur bacterium, (.) , contains a multigene family that encodes a series of α- and β-polypeptides, collectively forming a heterogeneous ...The genome of the mildly thermophilic hot spring purple sulfur bacterium, (.) , contains a multigene family that encodes a series of α- and β-polypeptides, collectively forming a heterogeneous light-harvesting 1 (LH1) complex. The LH1, therefore, offers a unique model for studying an intermediate phenotype between phototrophic thermophilic and mesophilic bacteria, particularly regarding their LH1 transition and moderately enhanced thermal stability. Of the 16 α-polypeptides in the LH1, six α1 bind Ca to connect with β1- or β3-polypeptides in specific Ca-binding sites. Here, we use the purple bacterium strain H2 as a host to express Ca-bound and Ca-free LH1-only complexes composed of α- and β-polypeptides that either contain or lack the calcium-binding motif WxxDxI; purified preparations of each complex were then used to test how Ca affects their thermostability and spectral features. The cryo-EM structures of both complexes were closed circular rings consisting of 14 αβ-polypeptides. The absorption maximum of Ca-bound LH1 (α1/β1 and α1/β3) was at 894 nm, while that of Ca-free (α2/β1) was at 888 nm, indicating that Ca imparts a transition of 6 nm. Crucially for the ecological success of , Ca-bound LH1 complexes were more thermostable than Ca-free complexes, indicating that calcium plays at least two major roles in photosynthesis by -improving photocomplex stability and modifying its spectrum. | ||||||
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Structure visualization
Structure viewer | Molecule: ![]() ![]() |
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Downloads & links
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Download
PDBx/mmCIF format | ![]() | 263.7 KB | Display | ![]() |
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PDB format | ![]() | 233 KB | Display | ![]() |
PDBx/mmJSON format | ![]() | Tree view | ![]() | |
Others | ![]() |
-Validation report
Arichive directory | ![]() ![]() | HTTPS FTP |
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-Related structure data
Related structure data | ![]() 39477MC ![]() 8ypbC C: citing same article ( M: map data used to model this data |
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Similar structure data | Similarity search - Function & homology ![]() |
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Links
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Assembly
Deposited unit | ![]()
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1 |
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Components
#1: Protein/peptide | Mass: 5269.103 Da / Num. of mol.: 14 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() Production host: ![]() References: UniProt: O82943 #2: Protein/peptide | Mass: 5108.121 Da / Num. of mol.: 14 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() Production host: ![]() #3: Chemical | ChemComp-BCL / #4: Chemical | ChemComp-CRT / Has ligand of interest | Y | Has protein modification | N | |
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-Experimental details
-Experiment
Experiment | Method: ELECTRON MICROSCOPY |
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EM experiment | Aggregation state: PARTICLE / 3D reconstruction method: single particle reconstruction |
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Sample preparation
Component | Name: LH1 COMPLEX / Type: COMPLEX / Entity ID: #1-#2 / Source: RECOMBINANT |
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Molecular weight | Experimental value: NO |
Source (natural) | Organism: ![]() |
Source (recombinant) | Organism: ![]() |
Buffer solution | pH: 7.5 |
Specimen | Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES |
Vitrification | Cryogen name: ETHANE |
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Electron microscopy imaging
Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company |
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Microscopy | Model: TFS KRIOS |
Electron gun | Electron source: ![]() |
Electron lens | Mode: BRIGHT FIELD / Nominal defocus max: 2200 nm / Nominal defocus min: 800 nm |
Image recording | Electron dose: 60 e/Å2 / Film or detector model: GATAN K3 (6k x 4k) |
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Processing
EM software | Name: PHENIX / Version: 1.19.2_4158: / Category: model refinement | ||||||||||||||||||||||||
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CTF correction | Type: PHASE FLIPPING ONLY | ||||||||||||||||||||||||
3D reconstruction | Resolution: 2.78 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 199061 / Symmetry type: POINT | ||||||||||||||||||||||||
Refine LS restraints |
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