Site-specific conformational alteration of the Oct-1 POU domain-DNA complex as the basis for differential recognition by Vmw65 (VP16)

Cell. 1994 Dec 2;79(5):841-52. doi: 10.1016/0092-8674(94)90073-6.


We show that the presence of a regulatory cis-acting element that flanks the core octamer site and dictates selectivity in the response to Vmw65 (VP16), while dispensable for POU binding per se, induces a conformational alteration in the nature of the POU domain in the DNA complex. A single substitution in the flanking signal distorts the POU complex and without affecting overall POU binding prevents Vmw65 interaction. Alternatively, substitution of a residue in the homeodomain predicted to contact the GARAT region prevents its recognition even on a wild-type motif, causing a reversion to the DNA binding pattern seen on a cellular motif and at the same time inefficient recognition by Vmw65. The results indicate that Vmw65 recognizes a particular POU domain conformation induced by the presence of the flanking GARAT region.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • DNA / metabolism*
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • HeLa Cells
  • Herpes Simplex Virus Protein Vmw65 / metabolism*
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / metabolism
  • Host Cell Factor C1
  • Humans
  • Models, Molecular
  • Molecular Sequence Data
  • Nucleic Acid Conformation
  • Octamer Transcription Factor-1
  • POU Domain Factors
  • Protein Binding
  • Protein Conformation
  • Regulatory Sequences, Nucleic Acid*
  • Structure-Activity Relationship
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Transcription, Genetic
  • Transcriptional Activation


  • DNA-Binding Proteins
  • HCFC1 protein, human
  • Herpes Simplex Virus Protein Vmw65
  • Homeodomain Proteins
  • Host Cell Factor C1
  • Octamer Transcription Factor-1
  • POU Domain Factors
  • POU2F1 protein, human
  • Transcription Factors
  • DNA