Fig. 2: Cryo-EM structure of PsCas9.
From: Engineered PsCas9 enables therapeutic genome editing in mouse liver with lipid nanoparticles
a Domain architecture of PsCas9. b 2.9 Å-resolution cryo-EM reconstruction of PsCas9 in the productive state. Both target and non-target strands (TS and NTS, respectively) have been cleaved, and the HNH domain remains positioned at the scissile phosphate of the TS. c Cartoon representation of PsCas9 model. d Structural basis of NGG PAM recognition. e Comparison of PsCas9 (green cartoon) with FnCas9 (orange cartoon, PDB ID 5B2O). The crystal structure of FnCas9 represents a dead-end, non-productive state, where the HNH domain is positioned far from the cleavage position of the TS. In the productive state, HNH is shifted by up to ~60 Å to the centre of the target strand. The REC and NUC lobes are largely consistent otherwise.
