3JA8
Cryo-EM structure of the MCM2-7 double hexamer
Summary for 3JA8
| Entry DOI | 10.2210/pdb3ja8/pdb |
| EMDB information | 6338 |
| Descriptor | Minichromosome Maintenance 2, Minichromosome Maintenance 3, Minichromosome Maintenance 4, ... (7 entities in total) |
| Functional Keywords | cryo-em, single particle, mcm2-7, dna replication, hydrolase |
| Biological source | Saccharomyces cerevisiae S288c (yeast) More |
| Total number of polymer chains | 6 |
| Total formula weight | 608932.45 |
| Authors | |
| Primary citation | Li, N.,Zhai, Y.,Zhang, Y.,Li, W.,Yang, M.,Lei, J.,Tye, B.K.,Gao, N. Structure of the eukaryotic MCM complex at 3.8 angstrom Nature, 524:186-191, 2015 Cited by PubMed 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 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. PubMed: 26222030DOI: 10.1038/nature14685 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (3.8 Å) |
Structure validation
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