Ontology highlight
ABSTRACT:
SUBMITTER: Xiao Y
PROVIDER: S-EPMC5841471 | biostudies-literature | 2017 Jun
REPOSITORIES: biostudies-literature
Xiao Yibei Y Luo Min M Hayes Robert P RP Kim Jonathan J Ng Sherwin S Ding Fang F Liao Maofu M Ke Ailong A
Cell 20170601 1
Type I CRISPR systems feature a sequential dsDNA target searching and degradation process, by crRNA-displaying Cascade and nuclease-helicase fusion enzyme Cas3, respectively. Here we present two cryo-EM snapshots of the Thermobifida fusca type I-E Cascade: (1) unwinding 11 bp of dsDNA at the seed-sequence region to scout for sequence complementarity, and (2) further unwinding of the entire protospacer to form a full R-loop. These structures provide the much-needed temporal and spatial resolution ...[more]