4XQK

ATP-dependent Type ISP restriction-modification enzyme LlaBIII bound to DNA

4XQK の概要

• エントリーDOI: 10.2210/pdb4xqk/pdb
• 分子名称: LlaBIII, DNA (28-MER), POTASSIUM ION, ... (5 entities in total)
• 機能のキーワード: atp-dependent restriction-modification enzyme, type isp restriction-modification enzyme, atpase, hydrolase-dna complex, hydrolase/dna
• 由来する生物種: Lactococcus lactis subsp. cremoris; 詳細
• タンパク質・核酸の鎖数: 6
• 化学式量合計: 394904.64

構造登録者

Chand, M.K.,Saikrishnan, K. (登録日: 2015-01-19, 公開日: 2015-09-16, 最終更新日: 2024-03-20)

主引用文献

Chand, M.K.,Nirwan, N.,Diffin, F.M.,Aelst, K.V.,Kulkarni, M.,Pernstich, C.,Szczelkun, M.D.,Saikrishnan, K.
Translocation-coupled DNA cleavage by the Type ISP restriction-modification enzymes
Nat.Chem.Biol., 11:870-877, 2015

PubMed Abstract: Production of endonucleolytic double-strand DNA breaks requires separate strand cleavage events. Although catalytic mechanisms for simple, dimeric endonucleases are known, there are many complex nuclease machines that are poorly understood. Here we studied the single polypeptide Type ISP restriction-modification (RM) enzymes, which cleave random DNA between distant target sites when two enzymes collide after convergent ATP-driven translocation. We report the 2.7-Å resolution X-ray crystal structure of a Type ISP enzyme-DNA complex, revealing that both the helicase-like ATPase and nuclease are located upstream of the direction of translocation, an observation inconsistent with simple nuclease-domain dimerization. Using single-molecule and biochemical techniques, we demonstrate that each ATPase remodels its DNA-protein complex and translocates along DNA without looping it, leading to a collision complex in which the nuclease domains are distal. Sequencing of the products of single cleavage events suggests a previously undescribed endonuclease model, where multiple, stochastic strand-nicking events combine to produce DNA scission.

PubMed: 26389736
DOI: 10.1038/nchembio.1926

実験手法

X-RAY DIFFRACTION (2.7 Å)