Molecular basis of cyclic tetra-oligoadenylate processing by small standalone CRISPR-Cas ring nucleases.
Molecular basis of cyclic tetra-oligoadenylate processing by small standalone CRISPR-Cas ring nucleases.
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DOI：
10.1093/nar/gkac923
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发表时间：
2022-10-28
影响因子：
14.9
通讯作者：
Montoya, Guillermo
中科院分区：
文献类型：
--
作者：
Molina, Rafael;Garcia-Martin, Ricardo;Lopez-Mendez, Blanca;Jensen, Anne Louise Gron;Ciges-Tomas, J. Rafael;Marchena-Hurtado, Javier;Stella, Stefano;Montoya, Guillermo
独立环核酸酶是CRISPR辅助蛋白，其通过切割环状寡腺苷酸（cA）第二信使下调III型CRISPR-Cas系统的免疫应答。在冰岛硫化叶菌（Sulfolobus islandicus）基因组中发现了两个具有这种功能的基因。它们编码由与HTH结构域融合的CARF结构域组成的长多肽和由具有40个残基C-末端插入的CARF结构域组成的短多肽。在这里，我们确定的载脂蛋白和底物的Sis 0455酶的结合状态的结构，揭示了在CARF结构域的C-末端区域的插入，这起着关键作用，关闭底物结合后的催化位点。我们的分析揭示了Sis 0455在切割过程中的关键残基，以及活性位点与其定位的偶联，以进行cA 4磷酸二酯水解。短的，Sis 0455，和长环核酸酶，Sis 0811之间的cA 4裂解的时间过程比较，前者的裂解动力学较慢，这表明这两种类型的酶在基因组中具有相同的功能的组合可能是一种进化策略，以调节在不同的感染情况下的第二信使的水平。
Standalone ring nucleases are CRISPR ancillary proteins, which downregulate the immune response of Type III CRISPR-Cas systems by cleaving cyclic oligoadenylates (cA) second messengers. Two genes with this function have been found within the Sulfolobus islandicus (Sis) genome. They code for a long polypeptide composed by a CARF domain fused to an HTH domain and a short polypeptide constituted by a CARF domain with a 40 residue C-terminal insertion. Here, we determine the structure of the apo and substrate bound states of the Sis0455 enzyme, revealing an insertion at the C-terminal region of the CARF domain, which plays a key role closing the catalytic site upon substrate binding. Our analysis reveals the key residues of Sis0455 during cleavage and the coupling of the active site closing with their positioning to proceed with cA4 phosphodiester hydrolysis. A time course comparison of cA4 cleavage between the short, Sis0455, and long ring nucleases, Sis0811, shows the slower cleavage kinetics of the former, suggesting that the combination of these two types of enzymes with the same function in a genome could be an evolutionary strategy to regulate the levels of the second messenger in different infection scenarios.
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影响因子：
64.8
作者：
通讯作者：
--
DOI：
10.1107/s0907444904019158
发表时间：
2004-12-01
影响因子：
2.2
作者：
Emsley, P;Cowtan, K
通讯作者：
Cowtan, K
影响因子：
56.9
作者：
Jinek, Martin;Chylinski, Krzysztof;Charpentier, Emmanuelle
通讯作者：
Charpentier, Emmanuelle
影响因子：
64.8
作者：
Athukoralage JS;Rouillon C;Graham S;Grüschow S;White MF
通讯作者：
White MF
影响因子：
16
作者：
Lau, Rebecca K.;Ye, Qiaozhen;Corbett, Kevin D.
通讯作者：
Corbett, Kevin D.