Cpf1 Is a Single RNA-Guided Endonuclease of a Class 2 CRISPR-Cas System
This paper characterizes Cpf1 (later named Cas12a) as a single-RNA-guided DNA endonuclease of a class 2 CRISPR-Cas system, expanding the genome-editing toolbox beyond Cas9. Cpf1 requires only a single crRNA (no tracrRNA), recognizes a T-rich PAM, and produces staggered cuts with overhangs. The authors demonstrate Cpf1-mediated genome editing in human cells.