8CSZ

IscB and wRNA bound to Target DNA

8CSZ の概要

• エントリーDOI: 10.2210/pdb8csz/pdb
• 関連するPDBエントリー: 7UTN
• EMDBエントリー: 26976
• 分子名称: IscB, RNA (222-MER), DNA target strand, ... (6 entities in total)
• 機能のキーワード: crispr, iscb, hearo rna, omega rna, rna binding protein-rna-dna complex, rna binding protein/rna/dna
• 由来する生物種: synthetic construct; 詳細
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 165802.11

構造登録者

Schuler, G.A.,Hu, C.,Ke, A. (登録日: 2022-05-13, 公開日: 2022-06-15, 最終更新日: 2025-05-14)

主引用文献

Schuler, G.,Hu, C.,Ke, A.
Structural basis for RNA-guided DNA cleavage by IscB-omega RNA and mechanistic comparison with Cas9.
Science, 376:1476-1481, 2022

PubMed Abstract: Class 2 CRISPR effectors Cas9 and Cas12 may have evolved from nucleases in IS200/IS605 transposons. IscB is about two-fifths the size of Cas9 but shares a similar domain organization. The associated ωRNA plays the combined role of CRISPR RNA (crRNA) and trans-activating CRISPR RNA tracrRNA) to guide double-stranded DNA (dsDNA) cleavage. Here we report a 2.78-angstrom cryo-electron microscopy structure of IscB-ωRNA bound to a dsDNA target, revealing the architectural and mechanistic similarities between IscB and Cas9 ribonucleoproteins. Target-adjacent motif recognition, R-loop formation, and DNA cleavage mechanisms are explained at high resolution. ωRNA plays the equivalent function of REC domains in Cas9 and contacts the RNA-DNA heteroduplex. The IscB-specific PLMP domain is dispensable for RNA-guided DNA cleavage. The transition from ancestral IscB to Cas9 involved dwarfing the ωRNA and introducing protein domain replacements.

PubMed: 35617371
DOI: 10.1126/science.abq7220

実験手法

ELECTRON MICROSCOPY (3.2 Å)