3WVO

Crystal structure of Thermobifida fusca Cse1

3WVO の概要

• エントリーDOI: 10.2210/pdb3wvo/pdb
• 分子名称: CRISPR-associated protein, Cse1 family (2 entities in total)
• 機能のキーワード: crispr, cascade, casa, cell invasion
• 由来する生物種: Thermobifida fusca
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 185485.49

構造登録者

Yuan, Y.A.,Tay, M. (登録日: 2014-06-02, 公開日: 2015-01-14, 最終更新日: 2023-11-08)

主引用文献

Tay, M.,Liu, S.,Yuan, Y.A.
Crystal structure of Thermobifida fusca Cse1 reveals target DNA binding site.
Protein Sci., 24:236-245, 2015

PubMed Abstract: The Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-CRISPR-associated (Cas) defense system is the only adaptive and inheritable immunity found in prokaryotes. The immunity is achieved through a multistep process of adaptation, expression, and interference. In the Type I-E system, interference is mediated by the CRISPR-associated complex for antiviral defense (Cascade), which recognizes invading double-stranded DNA (dsDNA) through the protospacer adjacent motif (PAM) by one of the Cascade components, Cse1. Here, we report the crystal structure of Thermobifida fusca Cse1 at 3.3 Å resolution. T. fusca Cse1 reveals the chair-like two-domain architecture with a well-defined flexible loop, L1, located at the larger N-terminal domain, which was not observed in previous structures of the single Cse1 protein. Structure-based mutagenesis analysis demonstrates that the well-defined flexible loop and a partially conserved structural motif ([FW]-X-[TH]) are involved in PAM binding and recognition, respectively. Moreover, structural docking of T. fusca Cse1 into Escherichia coli Cascade cryoelectron microscopy maps, coupled with structural comparison, reveals a conserved positive patch that is contiguous with Cse2 in the Cascade complex and adjacent to the Cas3 binding site, suggesting its role in R-loop formation/stabilization and the recruitment of Cas3 for target cleavage. Consistent with the structural observation, the introduction of alanine mutations at this positive patch abolished DNA binding activity by Cse1. Taken together, these results suggest that Cse1 is a critical Cascade component involved in Cascade assembly, dsDNA target recognition, R-loop formation, and Cas3 recruitment for target cleavage.

PubMed: 25420472
DOI: 10.1002/pro.2609

実験手法

X-RAY DIFFRACTION (3.31 Å)