+Open data
-Basic information
Entry | Database: EMDB / ID: EMD-43817 | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
Title | Human DNA polymerase theta helicase domain dimer, apo-form | |||||||||
Map data | ||||||||||
Sample |
| |||||||||
Keywords | DNA repair / helicase / ATPase / TRANSFERASE / DNA BINDING PROTEIN | |||||||||
Function / homology | Function and homology information single-stranded DNA endodeoxyribonuclease activity / HDR through MMEJ (alt-NHEJ) / double-strand break repair via alternative nonhomologous end joining / single-stranded DNA helicase activity / replication fork processing / site of DNA damage / negative regulation of double-strand break repair via homologous recombination / 5'-deoxyribose-5-phosphate lyase activity / error-prone translesion synthesis / somatic hypermutation of immunoglobulin genes ...single-stranded DNA endodeoxyribonuclease activity / HDR through MMEJ (alt-NHEJ) / double-strand break repair via alternative nonhomologous end joining / single-stranded DNA helicase activity / replication fork processing / site of DNA damage / negative regulation of double-strand break repair via homologous recombination / 5'-deoxyribose-5-phosphate lyase activity / error-prone translesion synthesis / somatic hypermutation of immunoglobulin genes / DNA helicase activity / base-excision repair / protein homooligomerization / RNA-directed DNA polymerase / RNA-directed DNA polymerase activity / double-strand break repair / site of double-strand break / DNA helicase / damaged DNA binding / DNA-directed DNA polymerase / DNA-directed DNA polymerase activity / DNA repair / DNA damage response / chromatin binding / Golgi apparatus / magnesium ion binding / ATP hydrolysis activity / nucleoplasm / ATP binding / identical protein binding / cytosol Similarity search - Function | |||||||||
Biological species | Homo sapiens (human) | |||||||||
Method | single particle reconstruction / cryo EM / Resolution: 3.6 Å | |||||||||
Authors | Ito F / Li Z / Chen XS | |||||||||
Funding support | United States, 1 items
| |||||||||
Citation | Journal: bioRxiv / Year: 2024 Title: Structural Basis for Polθ-Helicase DNA Binding and Microhomology-Mediated End-Joining. Authors: Fumiaki Ito / Ziyuan Li / Leonid Minakhin / Htet A Khant / Richard T Pomerantz / Xiaojiang S Chen / Abstract: DNA double-strand breaks (DSBs) present a critical threat to genomic integrity, often precipitating genomic instability and oncogenesis. Repair of DSBs predominantly occurs through homologous ...DNA double-strand breaks (DSBs) present a critical threat to genomic integrity, often precipitating genomic instability and oncogenesis. Repair of DSBs predominantly occurs through homologous recombination (HR) and non-homologous end joining (NHEJ). In HR-deficient cells, DNA polymerase theta (Polθ) becomes critical for DSB repair via microhomology-mediated end joining (MMEJ), also termed theta-mediated end joining (TMEJ). Thus, Polθ is synthetically lethal with BRCA1/2 and other HR factors, underscoring its potential as a therapeutic target in HR-deficient cancers. However, the molecular mechanisms governing Polθ-mediated MMEJ remain poorly understood. Here we present a series of cryo-electron microscopy structures of the Polθ helicase domain (Polθ-hel) in complex with DNA containing 3'-overhang. The structures reveal the sequential conformations adopted by Polθ-hel during the critical phases of DNA binding, microhomology searching, and microhomology annealing. The stepwise conformational changes within the Polθ-hel subdomains and its functional dimeric state are pivotal for aligning the 3'-overhangs, facilitating the microhomology search and subsequent annealing necessary for DSB repair via MMEJ. Our findings illustrate the essential molecular switches within Polθ-hel that orchestrate the MMEJ process in DSB repair, laying the groundwork for the development of targeted therapies against the Polθ-hel. | |||||||||
History |
|
-Structure visualization
Supplemental images |
---|
-Downloads & links
-EMDB archive
Map data | emd_43817.map.gz | 110.5 MB | EMDB map data format | |
---|---|---|---|---|
Header (meta data) | emd-43817-v30.xml emd-43817.xml | 15.3 KB 15.3 KB | Display Display | EMDB header |
FSC (resolution estimation) | emd_43817_fsc.xml | 12.7 KB | Display | FSC data file |
Images | emd_43817.png | 73.7 KB | ||
Filedesc metadata | emd-43817.cif.gz | 5.8 KB | ||
Others | emd_43817_half_map_1.map.gz emd_43817_half_map_2.map.gz | 200 MB 200 MB | ||
Archive directory | http://ftp.pdbj.org/pub/emdb/structures/EMD-43817 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-43817 | HTTPS FTP |
-Validation report
Summary document | emd_43817_validation.pdf.gz | 880.8 KB | Display | EMDB validaton report |
---|---|---|---|---|
Full document | emd_43817_full_validation.pdf.gz | 880.3 KB | Display | |
Data in XML | emd_43817_validation.xml.gz | 21.6 KB | Display | |
Data in CIF | emd_43817_validation.cif.gz | 28 KB | Display | |
Arichive directory | https://ftp.pdbj.org/pub/emdb/validation_reports/EMD-43817 ftp://ftp.pdbj.org/pub/emdb/validation_reports/EMD-43817 | HTTPS FTP |
-Related structure data
Related structure data | 9askMC 8w0aC 9asjC 9aslC 9c5qC 40760 40761 M: atomic model generated by this map C: citing same article (ref.) |
---|---|
Similar structure data | Similarity search - Function & homologyF&H Search |
-Links
EMDB pages | EMDB (EBI/PDBe) / EMDataResource |
---|---|
Related items in Molecule of the Month |
-Map
File | Download / File: emd_43817.map.gz / Format: CCP4 / Size: 216 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) | ||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Projections & slices | Image control
Images are generated by Spider. | ||||||||||||||||||||||||||||||||||||
Voxel size | X=Y=Z: 0.92 Å | ||||||||||||||||||||||||||||||||||||
Density |
| ||||||||||||||||||||||||||||||||||||
Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||
Details | EMDB XML:
|
-Supplemental data
-Half map: #1
File | emd_43817_half_map_1.map | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Projections & Slices |
| ||||||||||||
Density Histograms |
-Half map: #2
File | emd_43817_half_map_2.map | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Projections & Slices |
| ||||||||||||
Density Histograms |
-Sample components
-Entire : Human DNA polymerase theta helicase domain dimer, apo-form
Entire | Name: Human DNA polymerase theta helicase domain dimer, apo-form |
---|---|
Components |
|
-Supramolecule #1: Human DNA polymerase theta helicase domain dimer, apo-form
Supramolecule | Name: Human DNA polymerase theta helicase domain dimer, apo-form type: complex / ID: 1 / Parent: 0 / Macromolecule list: all |
---|---|
Source (natural) | Organism: Homo sapiens (human) |
Molecular weight | Theoretical: 199 KDa |
-Macromolecule #1: DNA polymerase theta
Macromolecule | Name: DNA polymerase theta / type: protein_or_peptide / ID: 1 / Number of copies: 2 / Enantiomer: LEVO / EC number: DNA-directed DNA polymerase |
---|---|
Source (natural) | Organism: Homo sapiens (human) |
Molecular weight | Theoretical: 99.802539 KDa |
Recombinant expression | Organism: Escherichia coli (E. coli) |
Sequence | String: MNLLRRSGKR RRSESGSDSF SGSGGDSSAS PQFLSGSVLS PPPGLGRCLK AAAAGECKPT VPDYERDKLL LANWGLPKAV LEKYHSFGV KKMFEWQAEC LLLGQVLEGK NLVYSAPTSA GKTLVAELLI LKRVLEMRKK ALFILPFVSV AKEKKYYLQS L FQEVGIKV ...String: MNLLRRSGKR RRSESGSDSF SGSGGDSSAS PQFLSGSVLS PPPGLGRCLK AAAAGECKPT VPDYERDKLL LANWGLPKAV LEKYHSFGV KKMFEWQAEC LLLGQVLEGK NLVYSAPTSA GKTLVAELLI LKRVLEMRKK ALFILPFVSV AKEKKYYLQS L FQEVGIKV DGYMGSTSPS RHFSSLDIAV CTIERANGLI NRLIEENKMD LLGMVVVDEL HMLGDSHRGY LLELLLTKIC YI TRKSASC QADLASSLSN AVQIVGMSAT LPNLELVASW LNAELYHTDF RPVPLLESVK VGNSIYDSSM KLVREFEPML QVK GDEDHV VSLCYETICD NHSVLLFCPS KKWCEKLADI IAREFYNLHH QAEGLVKPSE CPPVILEQKE LLEVMDQLRR LPSG LDSVL QKTVPWGVAF HHAGLTFEER DIIEGAFRQG LIRVLAATST LSSGVNLPAR RVIIRTPIFG GRPLDILTYK QMVGR AGRK GVDTVGESIL ICKNSEKSKG IALLQGSLKP VRSCLQRREG EEVTGSMIRA ILEIIVGGVA STSQDMHTYA ACTFLA ASM KEGKQGIQRN QESVQLGAIE ACVMWLLENE FIQSTEASDG TEGKVYHPTH LGSATLSSSL SPADTLDIFA DLQRAMK GF VLENDLHILY LVTPMFEDWT TIDWYRFFCL WEKLPTSMKR VAELVGVEEG FLARCVKGKV VARTERQHRQ MAIHKRFF T SLVLLDLISE VPLREINQKY GCNRGQIQSL QQSAAVYAGM ITVFSNRLGW HNMELLLSQF QKRLTFGIQR ELCDLVRVS LLNAQRARVL YASGFHTVAD LARANIVEVE VILKNAVPFK SARKAVDEEE EAVEERRNMR TIWVTGRKGL TEREAAALIV EEARMILQQ DLVEM UniProtKB: DNA polymerase theta |
-Experimental details
-Structure determination
Method | cryo EM |
---|---|
Processing | single particle reconstruction |
Aggregation state | particle |
-Sample preparation
Concentration | 1.0 mg/mL |
---|---|
Buffer | pH: 7.5 |
Vitrification | Cryogen name: ETHANE / Chamber humidity: 100 % / Chamber temperature: 277 K / Instrument: FEI VITROBOT MARK IV |
-Electron microscopy
Microscope | TFS GLACIOS |
---|---|
Image recording | Film or detector model: FEI FALCON IV (4k x 4k) / Number grids imaged: 1 / Number real images: 4511 / Average exposure time: 8.0 sec. / Average electron dose: 58.0 e/Å2 |
Electron beam | Acceleration voltage: 200 kV / Electron source: FIELD EMISSION GUN |
Electron optics | C2 aperture diameter: 50.0 µm / Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD / Cs: 2.0 mm / Nominal defocus max: 3.0 µm / Nominal defocus min: 1.0 µm / Nominal magnification: 150000 |