Structural flexibility in transcription complex formation revealed by protein-DNA photocrosslinking

Proc Natl Acad Sci U S A. 1997 Aug 5;94(16):8450-5. doi: 10.1073/pnas.94.16.8450.

Abstract

The Oct-1 POU domain binds diverse DNA-sequence elements and forms a higher-order regulatory complex with the herpes simplex virus coregulator VP16. The POU domain contains two separate DNA-binding domains joined by a flexible linker. By protein-DNA photocrosslinking we show that the relative positioning of the two POU DNA-binding domains on DNA varies depending on the nature of the DNA target. On a single VP16-responsive element, the POU domain adopts multiple conformations. To determine the structure of the Oct-1 POU domain in a multiprotein complex with VP16, we allowed VP16 to interact with previously crosslinked POU-domain-DNA complexes and found that VP16 can associate with multiple POU-domain conformations. These results reveal the dynamic potential of a DNA-binding domain in directing transcriptional regulatory complex formation.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Binding Sites
  • DNA / chemistry
  • DNA / genetics
  • DNA / metabolism*
  • DNA-Binding Proteins / chemistry
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Escherichia coli
  • Herpes Simplex Virus Protein Vmw65 / chemistry
  • Herpes Simplex Virus Protein Vmw65 / metabolism
  • Homeodomain Proteins / chemistry
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / metabolism*
  • Host Cell Factor C1
  • Humans
  • Octamer Transcription Factor-1
  • Protein Conformation
  • Transcription Factors / chemistry
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Transcription, Genetic*

Substances

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