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Schlagwörter:
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Zusammenfassung:
Swi2/Snf2 ATPases remodel substrates such as nucleosomes and
transcription complexes to control a wide range of DNA-associated
processes, but detailed structural information on the ATP-dependent
remodeling reactions is largely absent. The single subunit remodeler
Mot1 (modifier of transcription 1) dissociates TATA box-binding protein
(TBP):DNA complexes, offering a useful system to address the structural
mechanisms of Swi2/Snf2 ATPases. Here, we report the crystal structure
of the N-terminal domain of Mot1 in complex with TBP, DNA, and the
transcription regulator negative cofactor 2 (NC2). Our data show that
Mot1 reduces DNA:NC2 interactions and unbends DNA as compared to the
TBP:DNA:NC2 state, suggesting that Mot1 primes TBP:NC2 displacement in
an ATP-independent manner. Electron microscopy and cross-linking data
suggest that the Swi2/Snf2 domain of Mot1 associates with the upstream
DNA and the histone fold of NC2, thereby revealing parallels to some
nucleosome remodelers. This study provides a structural framework for
how a Swi2/Snf2 ATPase interacts with its substrate DNA:protein complex.
