An expanded search for RNA-programmable genomic engineering effectors

Abstract

A biocomputational pipeline was designed and implemented to mine through metagenomic datasets for novel Class 2 CRISPR (Clustered Regularly Interspaced Short Palindromic Repeat) single effectors, akin to the revolutionary genome-engineering tools Cas9 and Cpf1. Whereas previous search strategies relied on protein proximity to CRISPR-associated spacer acquisition proteins Cas1 and Cas2, this approach was seeded on CRISPR arrays alone. What resulted was the discovery of a potential new Class 2 CRISPR system, with two subtypes as characterized by distinct putative accessory proteins. Follow-up experimental work is required to assess the system's activity: first, in the presence and absence of the accessory protein; and second, as a single effector protein capable of precise genome engineering in prokaryotic and eukaryotic cells.