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Open data
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Basic information
| Entry | Database: PDB / ID: 5bk4 | ||||||
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| Title | Cryo-EM structure of Mcm2-7 double hexamer on dsDNA | ||||||
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Keywords | HYDROLASE/DNA / complex / DNA replication / HYDROLASE-DNA complex | ||||||
| Function / homology | Function and homology informationMCM 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 / replication fork protection complex / pre-replicative complex assembly involved in nuclear cell cycle DNA replication / Activation of the pre-replicative complex / mitotic DNA replication ...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 / replication fork protection complex / pre-replicative complex assembly involved in nuclear cell cycle DNA replication / Activation of the pre-replicative complex / mitotic DNA replication / CMG complex / nuclear pre-replicative complex / Activation of ATR in response to replication stress / DNA replication preinitiation complex / MCM complex / double-strand break repair via break-induced replication / mitotic DNA replication initiation / single-stranded DNA helicase activity / silent mating-type cassette heterochromatin formation / regulation of DNA-templated DNA replication initiation / DNA strand elongation involved in DNA replication / nuclear replication fork / DNA replication origin binding / DNA replication initiation / subtelomeric heterochromatin formation / DNA helicase activity / transcription elongation by RNA polymerase II / helicase activity / heterochromatin formation / single-stranded DNA binding / DNA helicase / 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: 3.9 Å | ||||||
Authors | Li, H. / Yuan, Z. / Bai, L. | ||||||
| Funding support | United States, 1items
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Citation | Journal: Proc Natl Acad Sci U S A / Year: 2017Title: Cryo-EM structure of Mcm2-7 double hexamer on DNA suggests a lagging-strand DNA extrusion model. Authors: Yasunori Noguchi / Zuanning Yuan / Lin Bai / Sarah Schneider / Gongpu Zhao / Bruce Stillman / Christian Speck / Huilin Li / ![]() Abstract: During replication initiation, the core component of the helicase-the Mcm2-7 hexamer-is loaded on origin DNA as a double hexamer (DH). The two ring-shaped hexamers are staggered, leading to a kinked ...During replication initiation, the core component of the helicase-the Mcm2-7 hexamer-is loaded on origin DNA as a double hexamer (DH). The two ring-shaped hexamers are staggered, leading to a kinked axial channel. How the origin DNA interacts with the axial channel is not understood, but the interaction could provide key insights into Mcm2-7 function and regulation. Here, we report the cryo-EM structure of the Mcm2-7 DH on dsDNA and show that the DNA is zigzagged inside the central channel. Several of the Mcm subunit DNA-binding loops, such as the oligosaccharide-oligonucleotide loops, helix 2 insertion loops, and presensor 1 (PS1) loops, are well defined, and many of them interact extensively with the DNA. The PS1 loops of Mcm 3, 4, 6, and 7, but not 2 and 5, engage the lagging strand with an approximate step size of one base per subunit. Staggered coupling of the two opposing hexamers positions the DNA right in front of the two Mcm2-Mcm5 gates, with each strand being pressed against one gate. The architecture suggests that lagging-strand extrusion initiates in the middle of the DH that is composed of the zinc finger domains of both hexamers. To convert the Mcm2-7 DH structure into the Mcm2-7 hexamer structure found in the active helicase, the N-tier ring of the Mcm2-7 hexamer in the DH-dsDNA needs to tilt and shift laterally. We suggest that these N-tier ring movements cause the DNA strand separation and lagging-strand extrusion. | ||||||
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Structure visualization
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| Structure viewer | Molecule: Molmil Jmol/JSmol |
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Downloads & links
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Download
| PDBx/mmCIF format | 5bk4.cif.gz | 1.4 MB | Display | PDBx/mmCIF format |
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| PDB format | pdb5bk4.ent.gz | 1.1 MB | Display | PDB format |
| PDBx/mmJSON format | 5bk4.json.gz | Tree view | PDBx/mmJSON format | |
| Others | Other downloads |
-Validation report
| Summary document | 5bk4_validation.pdf.gz | 1.4 MB | Display | wwPDB validaton report |
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| Full document | 5bk4_full_validation.pdf.gz | 1.4 MB | Display | |
| Data in XML | 5bk4_validation.xml.gz | 188.2 KB | Display | |
| Data in CIF | 5bk4_validation.cif.gz | 288.9 KB | Display | |
| Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/bk/5bk4 ftp://data.pdbj.org/pub/pdb/validation_reports/bk/5bk4 | HTTPS FTP |
-Related structure data
| Related structure data | ![]() 9400MC 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
-DNA replication licensing factor ... , 6 types, 12 molecules 2A3B4C5D6E7F
| #1: Protein | Mass: 98911.539 Da / Num. of mol.: 2 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() Gene: MCM2, YBL023C, YBL0438 / Production host: ![]() #2: Protein | Mass: 107653.508 Da / Num. of mol.: 2 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() Gene: MCM3, YEL032W, SYGP-ORF23 / Production host: ![]() #3: Protein | Mass: 105138.375 Da / Num. of mol.: 2 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() Gene: MCM4, CDC54, HCD21, YPR019W, YP9531.13 / Production host: ![]() #4: Protein | Mass: 86505.734 Da / Num. of mol.: 2 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() Gene: MCM5, CDC46, YLR274W, L9328.1 / Production host: ![]() #5: Protein | Mass: 113110.211 Da / Num. of mol.: 2 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() Gene: MCM6, YGL201C / Production host: ![]() #6: Protein | Mass: 95049.875 Da / Num. of mol.: 2 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() Gene: MCM7, CDC47, YBR202W, YBR1441 / Production host: ![]() |
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-DNA (60-mer), strand ... , 2 types, 2 molecules SO
| #7: DNA chain | Mass: 18491.848 Da / Num. of mol.: 1 / Source method: obtained synthetically / Source: (synth.) ![]() |
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| #8: DNA chain | Mass: 18491.848 Da / Num. of mol.: 1 / Source method: obtained synthetically / Source: (synth.) ![]() |
-Non-polymers , 1 types, 8 molecules 
| #9: Chemical | ChemComp-ADP / |
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-Details
| Has protein modification | 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 |
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Sample preparation
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| Source (recombinant) | Organism: ![]() | ||||||||||||||||||||||||
| Buffer solution | pH: 8 | ||||||||||||||||||||||||
| 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: FEI TITAN KRIOS |
| Electron gun | Electron source: FIELD EMISSION GUN / Accelerating voltage: 300 kV / Illumination mode: FLOOD BEAM |
| Electron lens | Mode: BRIGHT FIELD |
| Image recording | Electron dose: 10 e/Å2 / Film or detector model: GATAN K2 SUMMIT (4k x 4k) |
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Processing
| Software | Name: PHENIX / Version: 1.11.1_2575: / Classification: refinement | ||||||||||||||||||||||||||||||||||||||||||||||||||||
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| CTF correction | Type: NONE | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| 3D reconstruction | Resolution: 3.9 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 58772 / Symmetry type: POINT | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Refine LS restraints |
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About Yorodumi






United States, 1items
Citation
UCSF Chimera





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