Article

THAP proteins target specific DNA sites through bipartite recognition of adjacent major and minor grooves.

Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA.
Nature Structural & Molecular Biology (Impact Factor: 11.63). 12/2009; 17(1):117-23. DOI: 10.1038/nsmb.1742
Source: PubMed

ABSTRACT THAP-family C(2)CH zinc-coordinating DNA-binding proteins function in diverse eukaryotic cellular processes, such as transposition, transcriptional repression, stem-cell pluripotency, angiogenesis and neurological function. To determine the molecular basis for sequence-specific DNA recognition by THAP proteins, we solved the crystal structure of the Drosophila melanogaster P element transposase THAP domain (DmTHAP) in complex with a natural 10-base-pair site. In contrast to C(2)H(2) zinc fingers, DmTHAP docks a conserved beta-sheet into the major groove and a basic C-terminal loop into the adjacent minor groove. We confirmed specific protein-DNA interactions by mutagenesis and DNA-binding assays. Sequence analysis of natural and in vitro-selected binding sites suggests that several THAPs (DmTHAP and human THAP1 and THAP9) recognize a bipartite TXXGGGX(A/T) consensus motif; homology suggests THAP proteins bind DNA through a bipartite interaction. These findings reveal the conserved mechanisms by which THAP-family proteins engage specific chromosomal target elements.

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