title: A simple cipher governs DNA recognition by TAL effectors.
abstract: TAL effectors of plant pathogenic bacteria in the genus Xanthomonas bind host DNA and activate genes that contribute to disease or turn on defense. Target specificity depends on an effector-variable number of typically 34 amino acid repeats, but the mechanism of recognition is not understood. We show that a repeat-variable pair of residues specifies the nucleotides in the target site, one pair to one nucleotide, with no apparent context dependence. Our finding represents a previously unknown mechanism for protein-DNA recognition that explains TAL effector specificity, enables target site prediction, and opens prospects for use of TAL effectors in research and biotechnology.
authors.affiliation: Department of Plant Pathology and Bioinformatics and Computational Biology Program, Iowa State University, Ames, IA 50011, USA.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Moscou
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Bogdanove
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D001483:Base Sequence; D019295:Computational Biology; D018744:DNA, Plant / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism*; D008969:Molecular Sequence Data; D009711:Nucleotides / Q000378:metabolism; D012275:Oryza / Q000235:genetics* / Q000382:microbiology; D011401:Promoter Regions, Genetic; D040081:Protein Array Analysis; D020449:Repetitive Sequences, Amino Acid; D015533:Transcriptional Activation; D014974:Xanthomonas / Q000378:metabolism* / Q000472:pathogenicity
chemical_list: D001426:Bacterial Proteins; D018744:DNA, Plant; D004268:DNA-Binding Proteins; D009711:Nucleotides