title: Structural flexibility in transcription complex formation revealed by protein-DNA photocrosslinking.
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.
authors.affiliation: Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.
authors.forename: M A
authors.initials: MA
authors.lastname: Cleary
authors.forename: P S
authors.initials: PS
authors.lastname: Pendergrast
authors.forename: W
authors.initials: W
authors.lastname: Herr
mesh_terms: D001665:Binding Sites; D004247:DNA / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli; D017405:Herpes Simplex Virus Protein Vmw65 / Q000737:chemistry / Q000378:metabolism; D018398:Homeodomain Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051863:Host Cell Factor C1; D006801:Humans; D050811:Octamer Transcription Factor-1; D011487:Protein Conformation; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D004268:DNA-Binding Proteins; C497692:HCFC1 protein, human; D017405:Herpes Simplex Virus Protein Vmw65; D018398:Homeodomain Proteins; D051863:Host Cell Factor C1; D050811:Octamer Transcription Factor-1; C494165:POU2F1 protein, human; D014157:Transcription Factors; D004247:DNA