Database of articles cited by EMDB/PDB/SASBDB data

Keywords
Structure methods	All X-ray diffraction NMR electron microscopy small angle scattering neutron diffraction fiber diffraction powder diffraction infrared spectroscopy EPR fluorescence transfer theoretical model Hybrid
Author
Journal
IF	>30 >20 >10 >5 all

Title	Structure of eukaryotic CMG helicase at a replication fork and implications to replisome architecture and origin initiation.
Journal, issue, pages	Proc Natl Acad Sci U S A, Vol. 114, Issue 5, Page E697-E706, Year 2017
Publish date	Jan 31, 2017
Authors	Roxana Georgescu / Zuanning Yuan / Lin Bai / Ruda de Luna Almeida Santos / Jingchuan Sun / Dan Zhang / Olga Yurieva / Huilin Li / Michael E O'Donnell /
PubMed Abstract	The eukaryotic CMG (Cdc45, Mcm2-7, GINS) helicase consists of the Mcm2-7 hexameric ring along with five accessory factors. The Mcm2-7 heterohexamer, like other hexameric helicases, is shaped like a ...The eukaryotic CMG (Cdc45, Mcm2-7, GINS) helicase consists of the Mcm2-7 hexameric ring along with five accessory factors. The Mcm2-7 heterohexamer, like other hexameric helicases, is shaped like a ring with two tiers, an N-tier ring composed of the N-terminal domains, and a C-tier of C-terminal domains; the C-tier contains the motor. In principle, either tier could translocate ahead of the other during movement on DNA. We have used cryo-EM single-particle 3D reconstruction to solve the structure of CMG in complex with a DNA fork. The duplex stem penetrates into the central channel of the N-tier and the unwound leading single-strand DNA traverses the channel through the N-tier into the C-tier motor, 5'-3' through CMG. Therefore, the N-tier ring is pushed ahead by the C-tier ring during CMG translocation, opposite the currently accepted polarity. The polarity of the N-tier ahead of the C-tier places the leading Pol ε below CMG and Pol α-primase at the top of CMG at the replication fork. Surprisingly, the new N-tier to C-tier polarity of translocation reveals an unforeseen quality-control mechanism at the origin. Thus, upon assembly of head-to-head CMGs that encircle double-stranded DNA at the origin, the two CMGs must pass one another to leave the origin and both must remodel onto opposite strands of single-stranded DNA to do so. We propose that head-to-head motors may generate energy that underlies initial melting at the origin.
External links	Proc Natl Acad Sci U S A / PubMed:28096349 / PubMed Central
Methods	EM (single particle)
Resolution	4.9 - 6.2 Å
Structure data	8518 5u8s EMDB-8518, PDB-5u8s: Structure of eukaryotic CMG helicase at a replication fork Method: EM (single particle) / Resolution: 6.1 Å 8519 5u8t EMDB-8519, PDB-5u8t: Structure of Eukaryotic CMG Helicase at a Replication Fork and Implications Method: EM (single particle) / Resolution: 4.9 Å EMDB-8520: Structure of Eukaryotic CMG Helicase at a Replication Fork and Implications to Replisome Architecture and Origin Initiation Method: EM (single particle) / Resolution: 6.2 Å
Chemicals	ChemComp-ATP: ADENOSINE-5'-TRIPHOSPHATE / ATP, energy-carrying moleculeYM ChemComp-ANP: PHOSPHOAMINOPHOSPHONIC ACID-ADENYLATE ESTER / AMP-PNP, energy-carrying molecule analogueYM
Source	saccharomyces cerevisiae (brewer's yeast) saccharomyces cerevisiae (strain atcc 204508 / s288c) (yeast) synthetic construct (others)
Keywords	REPLICATION / CMG helicase / replisome / origin initiation / DNA polymerase / DNA replication