西亚试剂：Integrase-mediated spacer acquisition during CRISPR–Cas ada

发布时间：2025-09-07

Bacteria and archaea insert spacer sequences acquired from foreign DNAs into CRISPR loci to generate immunological memory. The Escherichia coli Cas1–Cas2 complex mediates spacer acquisition in vivo, but the molecular mechanism of this process is unknown. Here we show that the purified Cas1–Cas2 complex integrates oligonucleotide DNA substrates into acceptor DNA to yield products similar to those generated by retroviral integrases and transposases. Cas1 is the catalytic subunit and Cas2 substantially increases integration activity. Protospacer DNA with free 3′-OH ends and supercoiled target DNA are required, and integration occurs preferentially at the ends of CRISPR repeats and at sequences adjacent to cruciform structures abutting AT-rich regions, similar to the CRISPR leader sequence. Our results demonstrate the Cas1–Cas2 complex to be the minimal machinery that catalyses spacer DNA acquisition and explain the significance of CRISPR repeats in providing sequence and structural specificity for Cas1–Cas2-mediated adaptive immunity.

以上资料由西亚试剂：http://www.xiyashiji.com/ 提供

上一篇：西亚试剂:TAdvanced 不仅领先-Biometra 红色PCR家族最新力作
下一篇：西亚试剂:西亚试剂:盐酸酚苄明