+Open data
-Basic information
Entry | Database: PDB / ID: 8eah | |||||||||
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Title | SsoMCM hexamer bound to Mg/ADP-BeFx and 16-mer oligo-dT. Class 1 | |||||||||
Components |
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Keywords | REPLICATION / TRANSFERASE/DNA / Helicase / ATPase / TRANSFERASE-DNA complex | |||||||||
Function / homology | Function and homology information MCM complex / DNA duplex unwinding / helicase activity / single-stranded DNA binding / DNA helicase / DNA replication / ATP hydrolysis activity / ATP binding / identical protein binding Similarity search - Function | |||||||||
Biological species | Saccharolobus solfataricus P2 (archaea) synthetic construct (others) | |||||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 2.48 Å | |||||||||
Authors | Meagher, M. / Myasnikov, A. / Enemark, E.J. | |||||||||
Funding support | United States, 2items
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Citation | Journal: Int J Mol Sci / Year: 2022 Title: Two Distinct Modes of DNA Binding by an MCM Helicase Enable DNA Translocation. Authors: Martin Meagher / Alexander Myasnikov / Eric J Enemark / Abstract: A six-subunit ATPase ring forms the central hub of the replication forks in all domains of life. This ring performs a helicase function to separate the two complementary DNA strands to be replicated ...A six-subunit ATPase ring forms the central hub of the replication forks in all domains of life. This ring performs a helicase function to separate the two complementary DNA strands to be replicated and drives the replication machinery along the DNA. Disruption of this helicase/ATPase ring is associated with genetic instability and diseases such as cancer. The helicase/ATPase rings of eukaryotes and archaea consist of six minichromosome maintenance (MCM) proteins. Prior structural studies have shown that MCM rings bind one encircled strand of DNA in a spiral staircase, suggesting that the ring pulls this strand of DNA through its central pore in a hand-over-hand mechanism where the subunit at the bottom of the staircase dissociates from DNA and re-binds DNA one step above the staircase. With high-resolution cryo-EM, we show that the MCM ring of the archaeal organism binds an encircled DNA strand in two different modes with different numbers of subunits engaged to DNA, illustrating a plausible mechanism for the alternating steps of DNA dissociation and re-association that occur during DNA translocation. | |||||||||
History |
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-Structure visualization
Structure viewer | Molecule: MolmilJmol/JSmol |
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-Downloads & links
-Download
PDBx/mmCIF format | 8eah.cif.gz | 693.8 KB | Display | PDBx/mmCIF format |
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PDB format | pdb8eah.ent.gz | Display | PDB format | |
PDBx/mmJSON format | 8eah.json.gz | Tree view | PDBx/mmJSON format | |
Others | Other downloads |
-Validation report
Summary document | 8eah_validation.pdf.gz | 1.4 MB | Display | wwPDB validaton report |
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Full document | 8eah_full_validation.pdf.gz | 1.4 MB | Display | |
Data in XML | 8eah_validation.xml.gz | 95 KB | Display | |
Data in CIF | 8eah_validation.cif.gz | 145.9 KB | Display | |
Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/ea/8eah ftp://data.pdbj.org/pub/pdb/validation_reports/ea/8eah | HTTPS FTP |
-Related structure data
Related structure data | 27976MC 8eafC 8eagC 8eaiC 8eajC 8eakC 8ealC 8eamC C: citing same article (ref.) M: map data used to model this data |
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Similar structure data | Similarity search - Function & homologyF&H Search |
-Links
-Assembly
Deposited unit |
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1 |
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-Components
-Protein / DNA chain , 2 types, 7 molecules ABCDEFX
#1: Protein | Mass: 68641.961 Da / Num. of mol.: 6 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Saccharolobus solfataricus P2 (archaea) Strain: ATCC 35092 / DSM 1617 / JCM 11322 / P2 / Gene: MCM, SSO0774 / Plasmid: pEE078.1 / Production host: Escherichia coli BL21(DE3) (bacteria) / Variant (production host): -RIPL / References: UniProt: Q9UXG1, DNA helicase #2: DNA chain | | Mass: 4822.127 Da / Num. of mol.: 1 / Source method: obtained synthetically / Source: (synth.) synthetic construct (others) |
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-Non-polymers , 4 types, 31 molecules
#3: Chemical | ChemComp-ZN / #4: Chemical | ChemComp-MG / #5: Chemical | ChemComp-08T / [[[( #6: Water | ChemComp-HOH / | |
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-Details
Has ligand of interest | Y |
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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 |
-Sample preparation
Component | Name: SsoMCM hexamer bound to Mg/ADP-BeFx and 16-mer oligo-dT Class 1 Type: COMPLEX / Entity ID: #1-#2 / Source: MULTIPLE SOURCES |
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Source (natural) | Organism: Saccharolobus solfataricus P2 (archaea) |
Source (recombinant) | Organism: Escherichia coli (E. coli) / Strain: BL21(DE3)-RIPL / Plasmid: pEE078.1 |
Buffer solution | pH: 7.6 |
Specimen | Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES |
Vitrification | Cryogen name: ETHANE |
-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: FIELD EMISSION GUN / Accelerating voltage: 300 kV / Illumination mode: FLOOD BEAM |
Electron lens | Mode: BRIGHT FIELD / Nominal defocus max: 1800 nm / Nominal defocus min: 800 nm / Cs: 2.7 mm |
Image recording | Electron dose: 78 e/Å2 / Film or detector model: GATAN K3 (6k x 4k) |
-Processing
EM software |
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CTF correction | Details: Initial CTF was calculated by cryoSPARC Patch CTF. CTF parameters were refined during final homogeneous refinement in cryoSPARC. Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | |||||||||||||||||||||||||||||||||||||||||||||
Particle selection | Details: Particles were selected from a subset of micrographs with cryoSPARC blob picker. 2D class averages were calculated, selected and used as templates with cryoSPARC template picker. | |||||||||||||||||||||||||||||||||||||||||||||
Symmetry | Point symmetry: C1 (asymmetric) | |||||||||||||||||||||||||||||||||||||||||||||
3D reconstruction | Resolution: 2.48 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 1649356 / Num. of class averages: 1 / Symmetry type: POINT | |||||||||||||||||||||||||||||||||||||||||||||
Atomic model building | Protocol: OTHER / Space: REAL Details: Bond distance and angle restraints for a tetrahedral Zn2+ coordination were applied. Bond distance and angle restraints for a octahedral Mg2+ coordination were applied. | |||||||||||||||||||||||||||||||||||||||||||||
Atomic model building | PDB-ID: 6MII Pdb chain-ID: B / Accession code: 6MII / Source name: PDB / Type: experimental model |