电子显微镜研究嗜热硫化叶菌中的 III 型 CRISPR 机器。

Electron microscopy studies of Type III CRISPR machines in Sulfolobus solfataricus.

机构信息

*Institute of Structural Molecular Biology and Centre for Science at Extreme Conditions, University of Edinburgh, Edinburgh EH9 3JR, U.K.

出版信息

Biochem Soc Trans. 2013 Dec;41(6):1427-30. doi: 10.1042/BST20130166.

DOI:10.1042/BST20130166

PMID:24256232

Abstract

The CRISPR (clustered regularly interspaced short palindromic repeats) system is an adaptive immune system that targets viruses and other mobile genetic elements in bacteria and archaea. Cells store information of past infections in their genome in repeat-spacer arrays. After transcription, these arrays are processed into unit-length crRNA (CRISPR RNA) that is loaded into effector complexes encoded by Cas (CRISPR-associated) genes. CRISPR-Cas complexes target invading nucleic acid for degradation. CRISPR effector complexes have been classified into three main types (I-III). Type III effector complexes share the Cas10 subunit. In the present paper, we discuss the structures of the two Type III effector complexes from Sulfolobus solfataricus, SsoCSM (subtype III-A) and SsoCMR (subtype III-B), obtained by electron microscopy and single particle analysis. We also compare these structures with Cascade (CRISPR-associated complex for antiviral defence) and with the RecA nucleoprotein.

摘要

CRISPR（成簇规律间隔短回文重复序列）系统是一种适应性免疫系统，可靶向细菌和古菌中的病毒和其他移动遗传元件。细胞将其基因组中过去感染的信息以重复间隔阵列的形式储存。这些阵列在转录后被加工成单位长度的 crRNA（CRISPR RNA），并装载到由 Cas（CRISPR 相关）基因编码的效应复合物中。CRISPR-Cas 复合物靶向入侵的核酸进行降解。CRISPR 效应复合物已被分为三种主要类型（I-III）。III 型效应复合物具有 Cas10 亚基。在本文中，我们通过电子显微镜和单颗粒分析讨论了来自 Sulfolobus solfataricus 的两种 III 型效应复合物 SsoCSM（III-A 亚型）和 SsoCMR（III-B 亚型）的结构。我们还将这些结构与 Cascade（抗病毒防御相关的 CRISPR 相关复合物）和 RecA 核蛋白进行了比较。