Japan Agency for Medical Research and Development (AMED)
日本
Japan Society for the Promotion of Science (JSPS)
日本
引用
ジャーナル: Nat Commun / 年: 2026 タイトル: Engineering a compact high-fidelity Staphylococcus aureus Cas9 variant with broader targeting range and mechanistic insights into its activation. 著者: Satoshi N Omura / Ryoya Nakagawa / Shohei Kajimoto / Sae Okazaki / Soh Ishiguro / Hideto Mori / Kosuke Onishi / Yuji Kashiwakura / Takafumi Hiramoto / Kio Horinaka / Mamoru Tanaka / Hisato ...著者: Satoshi N Omura / Ryoya Nakagawa / Shohei Kajimoto / Sae Okazaki / Soh Ishiguro / Hideto Mori / Kosuke Onishi / Yuji Kashiwakura / Takafumi Hiramoto / Kio Horinaka / Mamoru Tanaka / Hisato Hirano / Kasey Jividen / Keitaro Yamashita / Shengdar Q Tsai / Nozomu Yachie / Tsukasa Ohmori / Hiroshi Nishimasu / Osamu Nureki / 要旨: Staphylococcus aureus Cas9 (SaCas9) is smaller than the widely used Streptococcus pyogenes Cas9 (SpCas9) and has been harnessed for gene therapy using an adeno-associated virus vector. However, ...Staphylococcus aureus Cas9 (SaCas9) is smaller than the widely used Streptococcus pyogenes Cas9 (SpCas9) and has been harnessed for gene therapy using an adeno-associated virus vector. However, SaCas9 requires a longer NNGRRT (where N is any nucleotide and R is A or G) protospacer adjacent motif (PAM) for target DNA recognition, thereby restricting the targeting range. Although PAM-relaxed Cas9 variants have been developed, expanded targeting is often accompanied by compromised target specificity. Here, we report the rational engineering of eSaCas9-NNG, a SaCas9 variant that recognizes relaxed NNG PAMs while maintaining high target fidelity, thereby overcoming a fundamental trade-off in Cas9-based genome editing. eSaCas9-NNG efficiently induces indels and base conversions at endogenous sites bearing NNG PAMs in human cells and mice, with editing efficiencies comparable to those of other PAM-relaxed nucleases, including SpRY, SpG, and iGeoCas9, but with reduced off-target activity. We further determine the cryo-electron microscopy structures of eSaCas9-NNG in five distinct functional states, revealing the structural basis for its relaxed PAM recognition, improved target specificity, and nuclease activation. Overall, our findings demonstrate that eSaCas9-NNG could be used as a versatile genome editing tool for in vivo gene therapy, and improve our mechanistic understanding of the diverse CRISPR-Cas9 nucleases.