TAL effectors specificity stems from negative discrimination.
TAL effectors specificity stems from negative discrimination.
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DOI：
10.1371/journal.pone.0080261
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发表时间：
2013
期刊：
影响因子：
3.7
通讯作者：
Dal Peraro M
中科院分区：
文献类型：
--
作者：
Wicky BI;Stenta M;Dal Peraro M
转录激活器样(TAL)效应器是由植物病原细菌分泌的DNA结合蛋白，通过与植物DNA启动子结合而干扰天然细胞功能。它们结构的关键元素是具有几乎相同序列的串联重复区域。大多数多态位于两个连续的氨基酸上，称为重复可变双残基(RVD)。RVD成分和靶核苷酸之间的直接联系的发现使TAL衍生的DNA结合工具的设计具有可编程的特异性，从而彻底改变了基因组工程领域。尽管有结构数据，但这种特异性的分子起源以及识别机制仍不清楚。对最近晶体结构的分子模拟表明，大部分蛋白质-DNA结合能来自DNA骨架和非可变残基之间的非特异性相互作用，而RVDS的贡献可以忽略不计。基于动力学和能量考虑，我们假设，虽然第一个RVD残基促进螺旋断裂--允许TAL作为DNA包裹的超螺旋折叠--但第二个残基通过对匹配的负面区分提供了特异性。此外，我们提出了一个简单的类似药效团的模型来合理化RVD-DNA相互作用，并解释关于共同亲和力和结合效率的实验结果。这里提出的解释范例提供了对这一优雅架构的更好理解，我们希望将允许改进TAL衍生的生物技术工具的设计。
Transcription Activator-Like (TAL) effectors are DNA-binding proteins secreted by phytopathogenic bacteria that interfere with native cellular functions by binding to plant DNA promoters. The key element of their architecture is a domain of tandem-repeats with almost identical sequences. Most of the polymorphism is located at two consecutive amino acids termed Repeat Variable Diresidue (RVD). The discovery of a direct link between the RVD composition and the targeted nucleotide allowed the design of TAL-derived DNA-binding tools with programmable specificities that revolutionized the field of genome engineering. Despite structural data, the molecular origins of this specificity as well as the recognition mechanism have remained unclear. Molecular simulations of the recent crystal structures suggest that most of the protein-DNA binding energy originates from non-specific interactions between the DNA backbone and non-variable residues, while RVDs contributions are negligible. Based on dynamical and energetic considerations we postulate that, while the first RVD residue promotes helix breaks – allowing folding of TAL as a DNA-wrapping super-helix – the second provides specificity through a negative discrimination of matches. Furthermore, we propose a simple pharmacophore-like model for the rationalization of RVD-DNA interactions and the interpretation of experimental findings concerning shared affinities and binding efficiencies. The explanatory paradigm presented herein provides a better comprehension of this elegant architecture and we hope will allow for improved designs of TAL-derived biotechnological tools.
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影响因子：
14.9
作者：
Li T;Huang S;Jiang WZ;Wright D;Spalding MH;Weeks DP;Yang B
通讯作者：
Yang B
影响因子：
56.9
作者：
Boch, Jens;Scholze, Heidi;Bonas, Ulla
通讯作者：
Bonas, Ulla
DOI：
10.1073/pnas.1019533108
发表时间：
2011-02-08
影响因子：
11.1
作者：
Mahfouz, Magdy M.;Li, Lixin;Zhu, Jian-Kang
通讯作者：
Zhu, Jian-Kang
用 TAL 效应器靶向 G：用 NN 和 NK 重复可变二残基构建的 TALEN 的活性比较
影响因子：
3.7
作者：
Christian ML;Demorest ZL;Starker CG;Osborn MJ;Nyquist MD;Zhang Y;Carlson DF;Bradley P;Bogdanove AJ;Voytas DF
通讯作者：
Voytas DF
影响因子：
4.4
作者：
JORGENSEN, WL;CHANDRASEKHAR, J;KLEIN, ML
通讯作者：
KLEIN, ML