Discovery Offers Starting Point for Better Gene-Editing Tools
Published:31 May2022    Source:Cornell University

CRISPR has ushered in the era of genomic medicine. A line of powerful tools has been developed from the popular CRISPR-Cas9 to cure genetic diseases. However, there is a last-mile problem -- these tools need to be effectively delivered into every cell of the patient, and most Cas9s are too big to be fitted into popular genome therapy vectors, such as the adenovirus-associated virus (AAV).

 
In new research, Cornell scientists provide an explanation for how this problem is solved by nature: they define with atomic precision how a transposon-derived system edits DNA in RNA-guided fashion. Transposons are mobile genetic elements inside bacteria. A lineage of transposon encodes IscB, which is less than half the size of Cas9 but equally capable of DNA editing. Replacing Cas9 with IscB would definitively solve the size problem.