Yuan, Z., Riera, A., Bai, L., Sun, J., Nandi, S., Spanos, C., Chen, Z. A., Barbon, M., Rappsilber, J., Stillman, B., Speck, C., Li, H. (March 2017) Structural basis of Mcm2-7 replicative helicase loading by ORC-Cdc6 and Cdt1. Nat Struct Mol Biol, 24 (3). pp. 316-324. ISSN 1545-9985 (Public Dataset)
Abstract
To initiate DNA replication, the origin recognition complex (ORC) and Cdc6 load an Mcm2-7 double hexamer onto DNA. Without ATP hydrolysis, ORC-Cdc6 recruits one Cdt1-bound Mcm2-7 hexamer, thus forming an ORC-Cdc6-Cdt1-Mcm2-7 (OCCM) helicase-loading intermediate. Here we report a 3.9-A structure of Saccharomyces cerevisiae OCCM on DNA. Flexible Mcm2-7 winged-helix domains (WHDs) engage ORC-Cdc6. A three-domain Cdt1 configuration embraces Mcm2, Mcm4, and Mcm6, thus comprising nearly half of the hexamer. The Cdt1 C-terminal domain extends to the Mcm6 WHD, which binds the Orc4 WHD. DNA passes through the ORC-Cdc6 and Mcm2-7 rings. Origin DNA interaction is mediated by an alpha-helix within Orc4 and positively charged loops within Orc2 and Cdc6. The Mcm2-7 C-tier AAA+ ring is topologically closed by an Mcm5 loop that embraces Mcm2, but the N-tier-ring Mcm2-Mcm5 interface remains open. This structure suggests a loading mechanism of the first Cdt1-bound Mcm2-7 hexamer by ORC-Cdc6.
| Item Type: | Paper |
|---|---|
| Subjects: | bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > DNA replication bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > enzymes > helicase bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > origin recognition complex |
| CSHL Authors: | |
| Communities: | CSHL labs > Stillman lab CSHL Cancer Center Program > Gene Regulation and Inheritance Program |
| Highlight: | Stillman, Bruce W. |
| Depositing User: | Matt Covey |
| Date: | March 2017 |
| Date Deposited: | 16 Feb 2017 21:36 |
| Last Modified: | 07 Jul 2021 19:04 |
| PMCID: | PMC5503505 |
| Related URLs: | |
| Dataset ID: | |
| URI: | https://repository.cshl.edu/id/eprint/34126 |
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