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Mechanisms for target recognition and cleavage by the Cas12i RNA-guided endonuclease.

ABSTRACT: Cas12i is a recently identified type V CRISPR-Cas endonuclease that predominantly cleaves the non-target strand of a double-stranded DNA substrate. This nicking activity of Cas12i could potentially be used for genome editing with high specificity. To elucidate its mechanisms for target recognition and cleavage, we determined cryo-EM structures of Cas12i in multiple functional states. Cas12i pre-orders a seven-nucleotide seed sequence of the crRNA for target recognition and undergoes a two-step activation through crRNA-DNA hybridization. Formation of 14 base pairs activates the nickase activity, and 28-bp hybridization promotes cleavage of the target strand. The atomic structures and mechanistic insights gained should facilitate the manipulation of Cas12i for genome editing applications.

SUBMITTER: Zhang H

PROVIDER: S-EPMC8256696 | biostudies-literature | 2020 Nov

REPOSITORIES: biostudies-literature

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Mechanisms for target recognition and cleavage by the Cas12i RNA-guided endonuclease.

Zhang Heng H Li Zhuang Z Xiao Renjian R Chang Leifu L

Nature structural & molecular biology 20200907 11

Cas12i is a recently identified type V CRISPR-Cas endonuclease that predominantly cleaves the non-target strand of a double-stranded DNA substrate. This nicking activity of Cas12i could potentially be used for genome editing with high specificity. To elucidate its mechanisms for target recognition and cleavage, we determined cryo-EM structures of Cas12i in multiple functional states. Cas12i pre-orders a seven-nucleotide seed sequence of the crRNA for target recognition and undergoes a two-step a ...[more]

PMID: 32895556

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