Programmable, multiplexed and orthogonal gene control in bacteria with attenuated Cas13d systems (opens in new tab)

Cas13-based RNA effectors may enable dynamic, multiplexed and reversible gene regulation in bacteria. Yet, their widespread adoption is hindered by inherent cytotoxicity and collateral cleavage. Here we present a rational protein engineering strategy to generate attenuated Cas13d variants with tunable RNase activity through targeted truncation of flexible regions. This permits effective transcript knockdown while greatly reducing toxicity as reflected by a 2.2-fold higher growth optical densi...