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Open data
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Basic information
Entry | Database: PDB / ID: 3ja8 | ||||||
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Title | Cryo-EM structure of the MCM2-7 double hexamer | ||||||
![]() | (Minichromosome Maintenance ...) x 6 | ||||||
![]() | HYDROLASE / Cryo-EM / single particle / MCM2-7 / DNA replication | ||||||
Function / homology | ![]() MCM core complex / Assembly of the pre-replicative complex / Switching of origins to a post-replicative state / MCM complex binding / nuclear DNA replication / premeiotic DNA replication / pre-replicative complex assembly involved in nuclear cell cycle DNA replication / mitotic DNA replication / Activation of the pre-replicative complex / CMG complex ...MCM core complex / Assembly of the pre-replicative complex / Switching of origins to a post-replicative state / MCM complex binding / nuclear DNA replication / premeiotic DNA replication / pre-replicative complex assembly involved in nuclear cell cycle DNA replication / mitotic DNA replication / Activation of the pre-replicative complex / CMG complex / nuclear pre-replicative complex / Activation of ATR in response to replication stress / DNA replication preinitiation complex / MCM complex / replication fork protection complex / double-strand break repair via break-induced replication / single-stranded DNA helicase activity / mitotic DNA replication initiation / regulation of DNA-templated DNA replication initiation / silent mating-type cassette heterochromatin formation / DNA strand elongation involved in DNA replication / nuclear replication fork / DNA replication origin binding / DNA replication initiation / subtelomeric heterochromatin formation / helicase activity / transcription elongation by RNA polymerase II / heterochromatin formation / single-stranded DNA binding / DNA helicase / forked DNA-dependent helicase activity / single-stranded 3'-5' DNA helicase activity / four-way junction helicase activity / double-stranded DNA helicase activity / chromosome, telomeric region / DNA replication / DNA damage response / chromatin binding / ATP hydrolysis activity / zinc ion binding / nucleoplasm / ATP binding / nucleus / cytoplasm Similarity search - Function | ||||||
Biological species | ![]() ![]() | ||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 3.8 Å | ||||||
![]() | Li, N. / Zhai, Y. / Zhang, Y. / Li, W. / Yang, M. / Lei, J. / Tye, B.K. / Gao, N. | ||||||
![]() | ![]() Title: Structure of the eukaryotic MCM complex at 3.8 Å. Authors: Ningning Li / Yuanliang Zhai / Yixiao Zhang / Wanqiu Li / Maojun Yang / Jianlin Lei / Bik-Kwoon Tye / Ning Gao / ![]() ![]() Abstract: DNA replication in eukaryotes is strictly regulated by several mechanisms. A central step in this replication is the assembly of the heterohexameric minichromosome maintenance (MCM2-7) helicase ...DNA replication in eukaryotes is strictly regulated by several mechanisms. A central step in this replication is the assembly of the heterohexameric minichromosome maintenance (MCM2-7) helicase complex at replication origins during G1 phase as an inactive double hexamer. Here, using cryo-electron microscopy, we report a near-atomic structure of the MCM2-7 double hexamer purified from yeast G1 chromatin. Our structure shows that two single hexamers, arranged in a tilted and twisted fashion through interdigitated amino-terminal domain interactions, form a kinked central channel. Four constricted rings consisting of conserved interior β-hairpins from the two single hexamers create a narrow passageway that tightly fits duplex DNA. This narrow passageway, reinforced by the offset of the two single hexamers at the double hexamer interface, is flanked by two pairs of gate-forming subunits, MCM2 and MCM5. These unusual features of the twisted and tilted single hexamers suggest a concerted mechanism for the melting of origin DNA that requires structural deformation of the intervening DNA. | ||||||
History |
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Structure visualization
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Structure viewer | Molecule: ![]() ![]() |
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Downloads & links
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PDBx/mmCIF format | ![]() | 705.8 KB | Display | ![]() |
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PDB format | ![]() | 554.3 KB | Display | ![]() |
PDBx/mmJSON format | ![]() | Tree view | ![]() | |
Others | ![]() |
-Validation report
Arichive directory | ![]() ![]() | HTTPS FTP |
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-Related structure data
Related structure data | ![]() 6338MC 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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1 |
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Components
-Minichromosome Maintenance ... , 6 types, 6 molecules 234567
#1: Protein | Mass: 98911.539 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) ![]() ![]() |
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#2: Protein | Mass: 107653.508 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) ![]() ![]() |
#3: Protein | Mass: 105138.375 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) ![]() ![]() |
#4: Protein | Mass: 86505.734 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) ![]() ![]() |
#5: Protein | Mass: 113110.211 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) ![]() ![]() |
#6: Protein | Mass: 95049.875 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) ![]() ![]() |
-Non-polymers , 1 types, 6 molecules 
#7: Chemical | ChemComp-ADP / |
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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: Eukaryotic Minichromosome Maintenance Complex / Type: COMPLEX |
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Molecular weight | Value: 1.2 MDa / Experimental value: NO |
Buffer solution | pH: 7.5 |
Specimen | Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES |
Vitrification | Instrument: FEI VITROBOT MARK IV / Cryogen name: ETHANE / Humidity: 100 % |
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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 / Date: Nov 25, 2015 |
Electron gun | Electron source: ![]() |
Electron lens | Mode: BRIGHT FIELD / Nominal magnification: 22500 X / Camera length: 0 mm |
Specimen holder | Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER / Tilt angle max: 0 ° / Tilt angle min: 0 ° |
Image recording | Electron dose: 22 e/Å2 / Film or detector model: GATAN K2 (4k x 4k) |
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Processing
EM software | Name: RELION / Category: 3D reconstruction | ||||||||||||
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CTF correction | Details: CTFFIND | ||||||||||||
Symmetry | Point symmetry: C2 (2 fold cyclic) | ||||||||||||
3D reconstruction | Resolution: 3.8 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 85365 / Details: (Single particle--Applied symmetry: C2) / Symmetry type: POINT | ||||||||||||
Refinement step | Cycle: LAST
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