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Direct CRISPR spacer acquisition from RNA by a natural reverse transcriptase-Cas1 fusion protein.

ABSTRACT: CRISPR systems mediate adaptive immunity in diverse prokaryotes. CRISPR-associated Cas1 and Cas2 proteins have been shown to enable adaptation to new threats in type I and II CRISPR systems by the acquisition of short segments of DNA (spacers) from invasive elements. In several type III CRISPR systems, Cas1 is naturally fused to a reverse transcriptase (RT). In the marine bacterium Marinomonas mediterranea (MMB-1), we showed that a RT-Cas1 fusion protein enables the acquisition of RNA spacers in vivo in a RT-dependent manner. In vitro, the MMB-1 RT-Cas1 and Cas2 proteins catalyze the ligation of RNA segments into the CRISPR array, which is followed by reverse transcription. These observations outline a host-mediated mechanism for reverse information flow from RNA to DNA.

SUBMITTER: Silas S

PROVIDER: S-EPMC4898656 | biostudies-literature | 2016 Feb

REPOSITORIES: biostudies-literature

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Direct CRISPR spacer acquisition from RNA by a natural reverse transcriptase-Cas1 fusion protein.

Silas Sukrit S Mohr Georg G Sidote David J DJ Markham Laura M LM Sanchez-Amat Antonio A Bhaya Devaki D Lambowitz Alan M AM Fire Andrew Z AZ

Science (New York, N.Y.) 20160201 6276

CRISPR systems mediate adaptive immunity in diverse prokaryotes. CRISPR-associated Cas1 and Cas2 proteins have been shown to enable adaptation to new threats in type I and II CRISPR systems by the acquisition of short segments of DNA (spacers) from invasive elements. In several type III CRISPR systems, Cas1 is naturally fused to a reverse transcriptase (RT). In the marine bacterium Marinomonas mediterranea (MMB-1), we showed that a RT-Cas1 fusion protein enables the acquisition of RNA spacers in ...[more]

PMID: 26917774

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