The structure of the Dead ringer-DNA complex reveals how AT-rich interaction domains (ARIDs) recognize DNA

Junji Iwahara, Mizuho Iwahara, Gary W. Daughdrill, Joseph Ford

Research output: Contribution to journalArticlepeer-review

55 Scopus citations


The AT-rich interaction domain (ARID) is a DNA-binding module found in many eukaryotic transcription factors. Using NMR spectroscopy, we have determined the first ever three-dimensional structure of an ARID-DNA complex (mol. wt 25.7 kDa) formed by Dead ringer from Drosophila melanogaster. ARIDs recognize DNA through a novel mechanism involving major groove immobilization of a large loop that connects the helices of a non-canonical helix-turn-helix motif, and through a concomitant structural rearrangement that produces stabilizing contacts from a β-hairpin. Dead ringer's preference for AT-rich DNA originates from three positions within the ARID fold that form energetically significant contacts to an adenine-thymine base step. Amino acids that dictate binding specificity are not highly conserved, suggesting that ARIDs will bind to a range of nucleotide sequences. Extended ARIDs, found in several sequence-specific transcription factors, are distinguished by the presence of a C-terminal helix that may increase their intrinsic affinity for DNA. The prevalence of serine amino acids at all specificity determining positions suggests that ARIDs within SWI/SNF-related complexes will interact with DNA non-sequence specifically.

Original languageEnglish (US)
Pages (from-to)1197-1209
Number of pages13
JournalEMBO Journal
Issue number5
StatePublished - Mar 1 2002
Externally publishedYes


  • ARID
  • AT-rich interaction domains
  • DNA recognition
  • Dead ringer
  • NMR
  • Structure

ASJC Scopus subject areas

  • General Neuroscience
  • Molecular Biology
  • General Biochemistry, Genetics and Molecular Biology
  • General Immunology and Microbiology


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