National Natural Science Foundation of China (NSFC)
中国
引用
ジャーナル: Proc Natl Acad Sci U S A / 年: 2023 タイトル: AcrIIC4 inhibits type II-C Cas9 by preventing R-loop formation. 著者: Wei Sun / Zhi Cheng / Jiuyu Wang / Jing Yang / Xueyan Li / Jinlong Wang / Minxuan Chen / Xiaoqi Yang / Gang Sheng / Jizhong Lou / Yanli Wang / 要旨: Anti-CRISPR (Acr) proteins are encoded by phages and other mobile genetic elements and inhibit host CRISPR-Cas immunity using versatile strategies. AcrIIC4 is a broad-spectrum Acr that inhibits the ...Anti-CRISPR (Acr) proteins are encoded by phages and other mobile genetic elements and inhibit host CRISPR-Cas immunity using versatile strategies. AcrIIC4 is a broad-spectrum Acr that inhibits the type II-C CRISPR-Cas9 system in several species by an unknown mechanism. Here, we determined a series of structures of Cas9 (HpaCas9)-sgRNA in complex with AcrIIC4 and/or target DNA, as well as the crystal structure of AcrIIC4 alone. We found that AcrIIC4 resides in the crevice between the REC1 and REC2 domains of HpaCas9, where its extensive interactions restrict the mobility of the REC2 domain and prevent the unwinding of target double-stranded (ds) DNA at the PAM-distal end. Therefore, the full-length guide RNA:target DNA heteroduplex fails to form in the presence of AcrIIC4, preventing Cas9 nuclease activation. Altogether, our structural and biochemical studies illuminate a unique Acr mechanism that allows DNA binding to the Cas9 effector complex but blocks its cleavage by preventing R-loop formation, a key step supporting DNA cleavage by Cas9.
分子量: 10072.395 Da / 分子数: 2 / 由来タイプ: 組換発現 詳細: WP_049372635.1;The first residue 'Ser' of the sample sequence is the one expressed from the vector left after tag cleavage. 由来: (組換発現) Haemophilus parainfluenzae (パラインフルエンザ菌) 遺伝子: acrIIC4 / 発現宿主: Escherichia coli BL21(DE3) (大腸菌)
構造決定の手法: 分子置換 開始モデル: in-house model ( the crystal structure of a SeMet-derivative of this protein using SAD) 解像度: 2.54→37.2 Å / SU ML: 0.2404 / 交差検証法: FREE R-VALUE / σ(F): 1.41 / 位相誤差: 22.6182 立体化学のターゲット値: GeoStd + Monomer Library + CDL v1.2
Rfactor
反射数
%反射
Rfree
0.2428
296
4.7 %
Rwork
0.2208
6006
-
obs
0.2218
6302
95.63 %
溶媒の処理
減衰半径: 0.9 Å / VDWプローブ半径: 1.11 Å / 溶媒モデル: FLAT BULK SOLVENT MODEL