Mechanisms used for cDNA synthesis and site-specific integration of RNA into DNA genomes by a reverse transcriptase-Cas1 fusion protein

Reverse transcriptase-Cas1 (RT-Cas1) fusion proteins found in some CRISPR systems enable spacer acquisition from both RNA and DNA, but the mechanism of RNA spacer acquisition has remained unclear. Here, we found that Marinomonas mediterranea RT-Cas1/Cas2 adds short 3'-DNA (dN) tails to RNA protospacers, enabling their direct integration into CRISPR arrays as 3'-dN-RNAs or 3'-dN-RNA/cDNA duplexes at rates comparable to similarly configured DNAs. Reverse transcription of RNA protospacers is initiated at 3' proximal sites by multiple mechanisms, including recently described de novo initiation, protein priming with any dNTP, and use of short exogenous or synthesized DNA oligomer primers, enabling synthesis of near full-length cDNAs of diverse RNAs without fixed sequence requirements. The integration of 3'-dN-RNAs or single-stranded DNAs (ssDNAs) is favored over duplexes at higher protospacer concentrations, potentially relevant to spacer acquisition from abundant pathogen RNAs or ssDNA fragments generated by phage defense nucleases. Our findings reveal mechanisms for site-specifically integrating RNA into DNA genomes with potential biotechnological applications.

Errataetall:

UpdateOf: bioRxiv. 2023 Sep 03;:. - PMID 37693417

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:10

Enthalten in:

Science advances - 10(2024), 15 vom: 12. Apr., Seite eadk8791

Sprache:

Englisch

Beteiligte Personen:

Mohr, Georg [VerfasserIn]
Yao, Jun [VerfasserIn]
Park, Seung Kuk [VerfasserIn]
Markham, Laura [VerfasserIn]
Lambowitz, Alan M [VerfasserIn]

Links:

Volltext

Themen:

63231-63-0
9007-49-2
DNA
DNA, Complementary
DNA, Single-Stranded
EC 2.7.7.49
Journal Article
RNA
RNA-Directed DNA Polymerase

Anmerkungen:

Date Completed 15.04.2024

Date Revised 25.04.2024

published: Print-Electronic

UpdateOf: bioRxiv. 2023 Sep 03;:. - PMID 37693417

Citation Status MEDLINE

doi:

10.1126/sciadv.adk8791

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM370973305