Snf2/Swi2-related ATPase Mot1 drives displacement of TATA-binding protein by gripping DNA

Rebekka O. Sprouse, Michael Brenowitz, David T. Auble

Research output: Contribution to journalArticle

35 Scopus citations

Abstract

Mot1 is a conserved Snf2/Swi2-related transcriptional regulator that uses ATP hydrolysis to displace TATA-binding protein (TBP) from DNA. Several models of the enzymatic mechanism have been proposed, including Mot1-catalyzed distortion of TBP structure, competition between Mot1 and DNA for the TBP DNA-binding surface, and ATP-driven translocation of Mot1 along DNA. Here, DNase I footprinting studies provide strong support for a 'DNA-based' mechanism of Mot1, which we propose involves ATP-driven DNA translocation. Mot1 forms an asymmetric complex with the TBP core domain (TBPc)-DNA complex, contacting DNA both upstream and within the major groove of the TATA Box. Contact with upstream DNA is required for Mot1-mediated displacement of TBPc from DNA. Using the SsoRad54-DNA complex as a model, DNA-binding residues in Mot1 were identified that are critical for Mot1-TBPc-DNA complex formation and catalytic activity, thus placing Mot1 mechanistically within the helicase superfamily. We also report a novel ATP-independent TBPc displacement activity for Mot1 and describe conformational heterogeneity in the Mot1 ATPase, which is likely a general feature of other enzymes in this class.

Original languageEnglish (US)
Pages (from-to)1492-1504
Number of pages13
JournalEMBO Journal
Volume25
Issue number7
DOIs
Publication statusPublished - Apr 5 2006

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Keywords

  • ATPase
  • Mot1
  • Snf2
  • Swi2
  • TBP

ASJC Scopus subject areas

  • Neuroscience(all)
  • Molecular Biology
  • Biochemistry, Genetics and Molecular Biology(all)
  • Immunology and Microbiology(all)

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