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Structural basis for sequence-specific recognition of DNA by TAL effectors.

ABSTRACT: TAL (transcription activator-like) effectors, secreted by phytopathogenic bacteria, recognize host DNA sequences through a central domain of tandem repeats. Each repeat comprises 33 to 35 conserved amino acids and targets a specific base pair by using two hypervariable residues [known as repeat variable diresidues (RVDs)] at positions 12 and 13. Here, we report the crystal structures of an 11.5-repeat TAL effector in both DNA-free and DNA-bound states. Each TAL repeat comprises two helices connected by a short RVD-containing loop. The 11.5 repeats form a right-handed, superhelical structure that tracks along the sense strand of DNA duplex, with RVDs contacting the major groove. The 12th residue stabilizes the RVD loop, whereas the 13th residue makes a base-specific contact. Understanding DNA recognition by TAL effectors may facilitate rational design of DNA-binding proteins with biotechnological applications.

SUBMITTER: Deng D

PROVIDER: S-EPMC3586824 | biostudies-literature | 2012 Feb

REPOSITORIES: biostudies-literature

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Structural basis for sequence-specific recognition of DNA by TAL effectors.

Deng Dong D Yan Chuangye C Pan Xiaojing X Mahfouz Magdy M Wang Jiawei J Zhu Jian-Kang JK Shi Yigong Y Yan Nieng N

Science (New York, N.Y.) 20120105 6069

TAL (transcription activator-like) effectors, secreted by phytopathogenic bacteria, recognize host DNA sequences through a central domain of tandem repeats. Each repeat comprises 33 to 35 conserved amino acids and targets a specific base pair by using two hypervariable residues [known as repeat variable diresidues (RVDs)] at positions 12 and 13. Here, we report the crystal structures of an 11.5-repeat TAL effector in both DNA-free and DNA-bound states. Each TAL repeat comprises two helices conne ...[more]

PMID: 22223738

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