タイプIIのCRISPR-Casが,Cas1-Cas2媒介のスペーサー統合によって免疫を確立する方法
Yibei Xiao1, Sherwin Ng1, Ki Hyun Nam2
1Department of Molecular Biology and Genetics, Cornell University, 253 Biotechnology Building, Ithaca, New York 14853, USA.
Nature
|September 5, 2017
まとめ
CRISPR-Casシステムは,Cas1-Cas2タンパク質を使用して,外来DNAスペーサーをCRISPR配列に統合し,適応免疫を形成します. この研究は,Enterococcus faecalisのスペーサー統合のステップ・バイ・ステップメカニズムを明らかにし,DNA曲線とリーダー・プロキシマル偏好を強調しています.
科学分野:
- 微生物学
- 分子生物学
- 遺伝学
背景:
- CRISPR-Casシステムは,外来遺伝子要素に対するRNA誘導の適応免疫を提供します.
- 異なったDNAをCRISPR配列に組み込むプロセスは 適応免疫に不可欠な保存メカニズムです
- 一般的なメカニズムは知られていますが,スペーサー統合中の正確な分子イベントとタンパク質の相互作用は,異なるCRISPR- Casタイプによって異なります.
研究 の 目的:
- Enterococcus faecalis のタイプII-A CRISPR-Cas システムにおける Cas1-Cas2 複合体によって媒介されるスペーサー統合の構造的および機械的詳細を解明する.
- Cas1-Cas2-プレスペーサー複合体の重要な統合段階における高解像度構造のスナップショットを提供する.
- 観察されたリーダー-近接統合の好みを説明するメカニズム的枠組みを開発する.
主な方法:
- プリスペーサーDNAに結合したEnterococcus faecalis Cas1-Cas2複合体の浄化と構造分析
- スパッサー統合プロセスの中間状態を捉える時間解析構造研究.
- タンパク質とDNAの相互作用と触媒作用を調査する生化学的測定法
主要な成果:
- Enterococcus faecalis Cas1-Cas2複合体は,特定の3'オーバーハングを持つスプレイドDNAプレスペーサーを選択的に結合する.
- 構造のスナップショットは3段階のプロセスを示しています ストキャスティック半サイト検索,リーダー近接CRISPRリピートへの優先結合,統合のための核愛的攻撃です
- DNAの折り曲げは,スペーサーの半部位置を認識するために不可欠であり,プレスペーサーをCRISPR配列に完全に統合することを容易にする.
結論:
- この研究は,Cas1-Cas2インテグラーゼ複合体によって駆動されるタイプII-ACRISPRスペーサー統合の詳細なメカニズムモデルを提供します.
- この発見は,DNA構成と特定のタンパク質とDNAの相互作用が,新しいスペーサーの優先的,近接的統合を導くことの重要性を強調しています.
- この研究はCRISPRベースの適応免疫の基礎となる 基本的な分子機構の理解を深めるものです
関連する概念動画
The Antiviral System of Bacteria and Archaea: CRISPR
801
CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats is a adaptive immune system found in bacteria and archaea that protects against viral infections. This system enables prokaryotic cells to identify, remember, and neutralize foreign genetic elements, primarily bacteriophages, by storing fragments of the invader’s DNA as a genetic memory.The CRISPR immune response begins during an initial infection. Cas (CRISPR-associated) proteins play a central role in this...
801
CRISPR and crRNAs
19.3K
Bacteria and archaea are susceptible to viral infections just like eukaryotes; therefore, they have developed a unique adaptive immune system to protect themselves. Clustered regularly interspaced short palindromic repeats and CRISPR-associated proteins (CRISPR-Cas) are present in more than 45% of known bacteria and 90% of known archaea.
The CRISPR-Cas system stores a copy of foreign DNA in the host genome and uses it to identify the foreign DNA upon reinfection. CRISPR-Cas has three different...
The CRISPR-Cas system stores a copy of foreign DNA in the host genome and uses it to identify the foreign DNA upon reinfection. CRISPR-Cas has three different...
19.3K
CRISPR/Cas9 Genome Editing
2.1K
The CRISPR-Cas system serves as a bacterial defense mechanism against invading genetic elements such as viruses and plasmids, forming the foundation for its adaptation as a powerful genome-editing tool. Originally discovered in prokaryotes, this system has been repurposed to revolutionize genetic engineering across a wide range of organisms, including plants, animals, and humans. The core component, Cas9, is an endonuclease derived from Streptococcus pyogenes, capable of introducing...
2.1K
CRISPR
58.2K
Genome editing technologies allow scientists to modify an organism’s DNA via the addition, removal, or rearrangement of genetic material at specific genomic locations. These types of techniques could potentially be used to cure genetic disorders such as hemophilia and sickle cell anemia. One popular and widely used DNA-editing research tool that could lead to safe and effective cures for genetic disorders is the CRISPR-Cas9 system. CRISPR-Cas9 stands for Clustered Regularly Interspaced...
58.2K
Homologous Recombination
64.2K
The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the...
64.2K
Conservative Site-specific Recombination and Phase Variation
6.9K
Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines.
The recognition sites for Cre recombinase called LoxP...
The recognition sites for Cre recombinase called LoxP...
6.9K


