| Structural highlights
4xgc is a 7 chain structure with sequence from Drome. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
| | Ligands: | , |
| NonStd Res: | |
| Gene: | Orc2, CG3041 (DROME), lat, CG34315-RB, lat-RA, CG4088, Dmel_CG4088 (DROME), Orc5, CG7833 (DROME), Orc1, CG10667 (DROME), Orc6, CG1584 (DROME), Orc4, CG2917, Dmel_CG2917 (DROME) |
| Activity: | Nucleoside-triphosphatase, with EC number 3.6.1.15 |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Function
[ORC6_DROME] Component of the origin recognition complex (ORC) that binds origins of replication. DNA-binding is ATP-dependent, however specific DNA sequences that define origins of replication have not been identified so far. ORC is required to assemble the pre-replication complex necessary to initiate DNA replication (By similarity). [ORC1_DROME] Component of the origin recognition complex (ORC) that binds origins of replication. DNA-binding is ATP-dependent, however specific DNA sequences that define origins of replication have not been identified so far. ORC is required to assemble the pre-replication complex necessary to initiate DNA replication.[1] [ORC2_DROME] Component of the origin recognition complex (ORC) that binds origins of replication. DNA-binding is ATP-dependent, however specific DNA sequences that define origins of replication have not been identified so far. ORC is required to assemble the pre-replication complex necessary to initiate DNA replication.[2] [ORC5_DROME] Component of the origin recognition complex (ORC) that binds origins of replication. DNA-binding is ATP-dependent, however specific DNA sequences that define origins of replication have not been identified so far. ORC is required to assemble the pre-replication complex necessary to initiate DNA replication (By similarity).
Publication Abstract from PubMed
Initiation of cellular DNA replication is tightly controlled to sustain genomic integrity. In eukaryotes, the heterohexameric origin recognition complex (ORC) is essential for coordinating replication onset. Here we describe the crystal structure of Drosophila ORC at 3.5 A resolution, showing that the 270 kilodalton initiator core complex comprises a two-layered notched ring in which a collar of winged-helix domains from the Orc1-5 subunits sits atop a layer of AAA+ (ATPases associated with a variety of cellular activities) folds. Although canonical inter-AAA+ domain interactions exist between four of the six ORC subunits, unanticipated features are also evident. These include highly interdigitated domain-swapping interactions between the winged-helix folds and AAA+ modules of neighbouring protomers, and a quasi-spiral arrangement of DNA binding elements that circumnavigate an approximately 20 A wide channel in the centre of the complex. Comparative analyses indicate that ORC encircles DNA, using its winged-helix domain face to engage the mini-chromosome maintenance 2-7 (MCM2-7) complex during replicative helicase loading; however, an observed out-of-plane rotation of more than 90 degrees for the Orc1 AAA+ domain disrupts interactions with catalytic amino acids in Orc4, narrowing and sealing off entry into the central channel. Prima facie, our data indicate that Drosophila ORC can switch between active and autoinhibited conformations, suggesting a novel means for cell cycle and/or developmental control of ORC functions.
Crystal structure of the eukaryotic origin recognition complex.,Bleichert F, Botchan MR, Berger JM Nature. 2015 Mar 19;519(7543):321-6. doi: 10.1038/nature14239. Epub 2015 Mar 11. PMID:25762138[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Pak DT, Pflumm M, Chesnokov I, Huang DW, Kellum R, Marr J, Romanowski P, Botchan MR. Association of the origin recognition complex with heterochromatin and HP1 in higher eukaryotes. Cell. 1997 Oct 31;91(3):311-23. PMID:9363940
- ↑ Loupart ML, Krause SA, Heck MS. Aberrant replication timing induces defective chromosome condensation in Drosophila ORC2 mutants. Curr Biol. 2000 Dec 14-28;10(24):1547-56. PMID:11137005
- ↑ Bleichert F, Botchan MR, Berger JM. Crystal structure of the eukaryotic origin recognition complex. Nature. 2015 Mar 19;519(7543):321-6. doi: 10.1038/nature14239. Epub 2015 Mar 11. PMID:25762138 doi:http://dx.doi.org/10.1038/nature14239
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