Breaking the code of DNA binding specificity of TAL-type III effectors.
The pathogenicity of many bacteria depends on the injection of effector proteins via type III secretion into eukaryotic cells in order to manipulate cellular processes. TAL (transcription activator-like) effectors from plant pathogenic Xanthomonas are important virulence factors that act as transcriptional activators in the plant cell nucleus, where they directly bind to DNA via a central domain of tandem repeats. Here, we show how target DNA specificity of TAL effectors is encoded. Two hypervariable amino acid residues in each repeat recognize one base pair in the target DNA. Recognition sequences of TAL effectors were predicted and experimentally confirmed. The modular protein architecture enabled the construction of artificial effectors with new specificities. Our study describes the functionality of a distinct type of DNA binding domain and allows the design of DNA binding domains for biotechnology.
Boch
Jens
J
Department of Genetics, Institute of Biology, Martin-Luther-University Halle-Wittenberg, Weinbergweg 10, D-06099 Halle (Saale) Germany. jens.boch@genetik.uni-halle.de
Scholze
Heidi
H
Schornack
Sebastian
S
Landgraf
Angelika
A
Hahn
Simone
S
Kay
Sabine
S
Lahaye
Thomas
T
Nickstadt
Anja
A
Bonas
Ulla
U
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D020029:Base Pairing; D001483:Base Sequence; D001709:Biotechnology; D002212:Capsicum / Q000235:genetics; D018744:DNA, Plant / Q000737:chemistry* / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism*; D017343:Genes, Plant; D008954:Models, Biological; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D020449:Repetitive Sequences, Amino Acid; D014026:Nicotiana / Q000235:genetics; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism; D015533:Transcriptional Activation; D014974:Xanthomonas / Q000378:metabolism* / Q000472:pathogenicity
D001426:Bacterial Proteins; D018744:DNA, Plant; D004268:DNA-Binding Proteins; D014157:Transcription Factors