Structure of eukaryotic CMG helicase at a replication fork and implications to replisome architecture and origin initiation Roxana Georgescu, Zuanning Yuan, Lin Bai, Ruda de Lun Almeida Santos, Jingchuan Sun, Dan Zhang, Olga Yurieva, Huilin Lic and Michael E. O’Donnell PNAS 2017 114 (5) E697-E706