Disintegration promotes protospacer integration by the Cas1-Cas2 complex.

ABSTRACT: 'Disintegration'-the reversal of transposon DNA integration at a target site-is regarded as an abortive off-pathway reaction. Here, we challenge this view with a biochemical investigation of the mechanism of protospacer insertion, which is mechanistically analogous to DNA transposition, by the Streptococcus pyogenes Cas1-Cas2 complex. In supercoiled target sites, the predominant outcome is the disintegration of one-ended insertions that fail to complete the second integration event. In linear target sites, one-ended insertions far outnumber complete protospacer insertions. The second insertion event is most often accompanied by the disintegration of the first, mediated either by the 3'-hydroxyl exposed during integration or by water. One-ended integration intermediates may mature in

SUBMITTER: Ma CH 

PROVIDER: S-EPMC8390005 | biostudies-literature | 2021 Aug

REPOSITORIES: biostudies-literature