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-Structure paper
Title | Quaternary structure of the human Cdt1-Geminin complex regulates DNA replication licensing. |
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Journal, issue, pages | Proc Natl Acad Sci U S A, Vol. 106, Issue 47, Page 19807-19812, Year 2009 |
Publish date | Nov 24, 2009 |
Authors | V De Marco / P J Gillespie / A Li / N Karantzelis / E Christodoulou / R Klompmaker / S van Gerwen / A Fish / M V Petoukhov / M S Iliou / Z Lygerou / R H Medema / J J Blow / D I Svergun / S Taraviras / A Perrakis / |
PubMed Abstract | All organisms need to ensure that no DNA segments are rereplicated in a single cell cycle. Eukaryotes achieve this through a process called origin licensing, which involves tight spatiotemporal ...All organisms need to ensure that no DNA segments are rereplicated in a single cell cycle. Eukaryotes achieve this through a process called origin licensing, which involves tight spatiotemporal control of the assembly of prereplicative complexes (pre-RCs) onto chromatin. Cdt1 is a key component and crucial regulator of pre-RC assembly. In higher eukaryotes, timely inhibition of Cdt1 by Geminin is essential to prevent DNA rereplication. Here, we address the mechanism of DNA licensing inhibition by Geminin, by combining X-ray crystallography, small-angle X-ray scattering, and functional studies in Xenopus and mammalian cells. Our findings show that the Cdt1:Geminin complex can exist in two distinct forms, a "permissive" heterotrimer and an "inhibitory" heterohexamer. Specific Cdt1 residues, buried in the heterohexamer, are important for licensing. We postulate that the transition between the heterotrimer and the heterohexamer represents a molecular switch between licensing-competent and licensing-defective states. |
External links | Proc Natl Acad Sci U S A / PubMed:19906994 / PubMed Central |
Methods | SAS (X-ray synchrotron) / X-ray diffraction |
Resolution | 3.3 Å |
Structure data | SASDAV3: SASDAW3: PDB-2wvr: |
Source |
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Keywords | REPLICATION / DNA REPLICATION LICENSE / DNA REPLICATION INHIBITOR / PHOSPHOPROTEIN / UBL CONJUGATION / DNA REPLICATION / DNA-BINDING / POLYMORPHISM / PROTO-ONCOGENE / NUCLEUS / CELL CYCLE / ACETYLATION / COILED COIL |