Breaking the Code of DNA Binding Specificity of TAL-Type III Effectors

  title={Breaking the Code of DNA Binding Specificity of TAL-Type III Effectors},
  author={Jens Boch and Heidi Scholze and Sebastian Schornack and Angelika Landgraf and Simone Hahn and Sabine Kay and Thomas Lahaye and Anja Nickstadt and Ulla Bonas},
  pages={1509 - 1512}
TAL Order Xanthomonas bacteria attack their plant hosts by delivering their own transcription-activator–like (TAL) proteins into the plant cell nucleus and alter the plant's gene regulation (see the Perspective by Voytas and Joung). Moscou and Bogdanove (p. 1501, published online 29 October: see the cover) and Boch et al. (p. 1509, published online 29 October) have now discovered how the similar but not identical repeats in the TAL proteins encode the specificity needed for the proteins to find… 

TAL effector-DNA specificity

The predicted DNA specificities of TAL effectors were predicted and artificial TAL proteins with novel DNA recognition specificities were generated, enabling design of proteins with potentially any given DNA recognition specificity enabling many uses for biotechnology.

Structural Basis for Sequence-Specific Recognition of DNA by TAL Effectors

Wrapped DNA TAL effectors are proteins that bacterial pathogens inject into plant cells that bind to host DNA to activate expression of plant genes. The DNA-binding domain of TAL proteins is composed

TAL effectors from Xanthomonas: design of a programmable DNA-binding specificity

A method called "Golden TAL Technology" is developed that allows a flexible assembly of TAL proteins with a designed order of repeats, which allows a simple reprogramming of DNA-binding specificity.

Predicting promoters targeted by TAL effectors in plant genomes: from dream to reality

An overview of the current tools and strategies that may be applied for finding targets of TAL effectors is given and several perspectives offered by these new tools are highlighted.

TAL effectors are remote controls for gene activation.

[Advances in transcription activator-like effectors--a review].

This work reviewed the development of this technology in multi-level and multi species, and its advantages and disadvantages compared with ZFNs and CRISPR/Cas technology, and addressed its special advantages in industrial microbe breeding, vector construction, targeting precision, high efficiency of editing and biological safety.

The Crystal Structure of TAL Effector PthXo1 Bound to Its DNA Target

The crystal structure of PthXo1 bound to its DNA target was determined by high-throughput computational structure prediction and validated by heavy-atom derivatization, and illustrates the basis of TAL effector–DNA recognition.

The Use and Development of TAL Effector Nucleases

The discovery of a novel DNA binding domain derived from transcription activator-like effectors of the plant pathogen genus Xanthomonas set the stage for the generation of various designer proteins by fusing tailored TALE-based DNA binding domains with either endonucleases, transcriptional modulators or chromatin remodeling domains with the final purpose to modify the genome, the transcriptome or the epigenome.

[Molecular recognition code between pathogenic bacterial TAL-effectors and host target genes: a review].

The findings and functions of TAL effectors, the binding specificity and recognition code between TAL-effectors and host target genes, and the possible applications and future prospects of the molecular recognition code have been discussed.



A Bacterial Effector Acts as a Plant Transcription Factor and Induces a Cell Size Regulator

It is shown that AvrBs3 induces the expression of a master regulator of cell size, upa20, which encodes a transcription factor containing a basic helix-loop-helix domain that provokes developmental reprogramming of host cells by mimicking eukaryotic transcription factors.

Detailed analysis of the DNA recognition motifs of the Xanthomonas type III effectors AvrBs3 and AvrBs3Deltarep16.

11 new UPA genes from bell pepper that are induced by AvrBs3 early after infection with Xcv are described and it is demonstrated that the UPA box corresponds to the center of the AvrBS3-protected DNA region.

Race-specificity of plant resistance to bacterial spot disease determined by repetitive motifs in a bacterial avirulence protein

It is reported here that the repetitive region of the avrBs3 gene determines race-specificity and that deletions of repeat units generate new avirulence specificities and unmask undiscovered resistance genes in pepper and tomato.

High frequency modification of plant genes using engineered zinc finger nucleases

High-frequency ZFN-stimulated gene targeting at endogenous plant genes, namely the tobacco acetolactate synthase genes (ALS SuRA and SuRB), for which specific mutations are known to confer resistance to imidazolinone and sulphonylurea herbicides are demonstrated.

The xanthomonas type III effector protein AvrBs3 modulates plant gene expression and induces cell hypertrophy in the susceptible host.

It is reported that infection of susceptible pepper and tomato plants leads to an AvrBs3-dependent hypertrophy of the mesophyll tissue, and that xanthomonads possess type III effectors that steer host gene expression.

Avoidance of host recognition by alterations in the repetitive and C-terminal regions of AvrXa7, a type III effector of Xanthomonas oryzae pv. oryzae.

The results demonstrated the potential for a critical virulence effector to lose avirulent activity while retaining effector function and demonstrated that features of both repetitive and nonrepetitive C-terminal regions of AvrXa7 are involved in avirulence specificity.

Expression levels of avrBs3-like genes affect recognition specificity in tomato Bs4- but not in pepper Bs3-mediated perception.

It is shown that Bs4 is constitutively expressed at low levels and that transcript abundance does not change significantly upon infection with avrBs4-containing xanthomonads, and that the protein levels expressed under control of the Bs 4 promoter are similar to those that are translocated by the bacterial type III secretion system.