title: Crystal structure of PU.1/IRF-4/DNA ternary complex.
abstract: The Ets and IRF transcription factor families contain structurally divergent members, PU.1, Spi-B and IRF-4 (Pip), IRF-8 (ICSBP), respectively, which have evolved to cooperatively assemble on composite DNA elements and regulate gene expression in the immune system. Whereas PU.1 recruits IRF-4 or IRF-8 to DNA, it exhibits an anticooperative interaction with IRF-1 and IRF-2. We report here the structure of the ternary complex formed with the DNA binding domains of PU.1 and IRF-4 on a composite DNA element. The DNA in the complex contorts into an unusual S shape that juxtaposes PU.1 and IRF-4 for selective electrostatic and hydrophobic interactions across the central minor groove. Together, the protein-protein and protein-DNA interactions provide insights into the stereochemical basis of cooperativity and anti-cooperativity between Ets and IRF factors.
authors.affiliation: Structural Biology Program, Department of Physiology and Biophysics, Mount Sinai School of Medicine, 1425 Madison Avenue, New York, NY 10029, USA.
authors.forename: Carlos R
authors.initials: CR
authors.lastname: Escalante
authors.forename: Abraham L
authors.initials: AL
authors.lastname: Brass
authors.forename: Jagan M R
authors.initials: JM
authors.lastname: Pongubala
authors.forename: Ella
authors.initials: E
authors.lastname: Shatova
authors.forename: Leyi
authors.initials: L
authors.lastname: Shen
authors.forename: Harinder
authors.initials: H
authors.lastname: Singh
authors.forename: Aneel K
authors.initials: AK
authors.lastname: Aggarwal
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D050835:Interferon Regulatory Factors; D051379:Mice; D008957:Models, Genetic; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011518:Proto-Oncogene Proteins / Q000737:chemistry* / Q000378:metabolism; D050783:Proto-Oncogene Proteins c-ets; D017386:Sequence Homology, Amino Acid; D015534:Trans-Activators / Q000737:chemistry* / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry* / Q000378:metabolism; D000099232:Proto-Oncogene Protein Spi-1; D000099218:Interferon Regulatory Factor-4
chemical_list: D004247:DNA; D004268:DNA-Binding Proteins; D050835:Interferon Regulatory Factors; D011518:Proto-Oncogene Proteins; D050783:Proto-Oncogene Proteins c-ets; D015534:Trans-Activators; D014157:Transcription Factors; D000099232:Proto-Oncogene Protein Spi-1; D000099218:Interferon Regulatory Factor-4