title: Structural basis of the TAL effector-DNA interaction.
abstract: Phytopathogen transcription activator-like effectors (TALEs) bind DNA in a sequence specific manner in order to manipulate host transcription. TALE specificity correlates with repeat variable diresidues in otherwise highly stereotypical 34-35mer repeats. Recently, the crystal structures of two TALE DNA-binding domains have illustrated the molecular basis of the TALE cipher. The structures show that the TALE repeats form a right-handed superhelix that is wound around largely undistorted B-DNA to match its helical parameters. Surprisingly, repeat variable residue 1 is not in contact with the bases. Instead, it is involved in hydrogen bonding interactions that stabilize the overall structure of the protein. Repeat variable residue 2 contacts the top strand base and forms sequence-specific hydrogen bonds and/or van der Waals contacts. Very unexpectedly, bottom strand bases are exposed to solvent and do not make any direct contacts with the protein. This review contains a summary of TALE biology and applications and a detailed description of the recent breakthroughs that have provided insights into the molecular basis of the TALE code.
authors.affiliation: International Institute of Molecular and Cell Biology, Trojdena 4, 02-109 Warsaw, Poland. mbochtler@iimcb.gov.pl
authors.forename: Matthias
authors.initials: M
authors.lastname: Bochtler
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001059:Apoproteins / Q000737:chemistry / Q000378:metabolism; D001483:Base Sequence; D018360:Crystallography, X-Ray; D004247:DNA / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D020449:Repetitive Sequences, Amino Acid; D037521:Virulence Factors / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D001059:Apoproteins; D037521:Virulence Factors; D004247:DNA