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Inhibition of CRISPR-Cas9 ribonucleoprotein complex assembly by anti-CRISPR AcrIIC2.

ABSTRACT: CRISPR-Cas adaptive immune systems function to protect bacteria from invasion by foreign genetic elements. The CRISPR-Cas9 system has been widely adopted as a powerful genome-editing tool, and phage-encoded inhibitors, known as anti-CRISPRs, offer a means of regulating its activity. Here, we report the crystal structures of anti-CRISPR protein AcrIIC2Nme alone and in complex with Nme1Cas9. We demonstrate that AcrIIC2Nme inhibits Cas9 through interactions with the positively charged bridge helix, thereby preventing sgRNA loading. In vivo phage plaque assays and in vitro DNA cleavage assays show that AcrIIC2Nme mediates its activity through a large electronegative surface. This work shows that anti-CRISPR activity can be mediated through the inhibition of Cas9 complex assembly.

SUBMITTER: Thavalingam A

PROVIDER: S-EPMC6594998 | biostudies-literature | 2019 Jun

REPOSITORIES: biostudies-literature

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Inhibition of CRISPR-Cas9 ribonucleoprotein complex assembly by anti-CRISPR AcrIIC2.

Thavalingam Annoj A Cheng Zhi Z Garcia Bianca B Huang Xue X Shah Megha M Sun Wei W Wang Min M Harrington Lucas L Hwang Sungwon S Hidalgo-Reyes Yurima Y Sontheimer Erik J EJ Doudna Jennifer J Davidson Alan R AR Moraes Trevor F TF Wang Yanli Y Maxwell Karen L KL

Nature communications 20190626 1

CRISPR-Cas adaptive immune systems function to protect bacteria from invasion by foreign genetic elements. The CRISPR-Cas9 system has been widely adopted as a powerful genome-editing tool, and phage-encoded inhibitors, known as anti-CRISPRs, offer a means of regulating its activity. Here, we report the crystal structures of anti-CRISPR protein AcrIIC2<sub>Nme</sub> alone and in complex with Nme1Cas9. We demonstrate that AcrIIC2<sub>Nme</sub> inhibits Cas9 through interactions with the positively ...[more]

PMID: 31243272

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