title: A flexible extension of the Drosophila ultrabithorax homeodomain defines a novel Hox/PBC interaction mode.
abstract: The patterning function of Hox proteins relies on assembling protein complexes with PBC proteins, which often involves a protein motif found in most Hox proteins, the so-called Hexapeptide (HX). Hox/PBC complexes likely gained functional diversity by acquiring additional modes of interaction. Here, we structurally characterize the first HX alternative interaction mode based on the paralogue-specific UbdA motif and further functionally validate structure-based predictions. The UbdA motif folds as a flexible extension of the homeodomain recognition helix and defines Hox/PBC contacts that occur, compared with those mediated by the HX motif, on the opposing side of the DNA double helix. This provides a new molecular facet to Hox/PBC complex assembly and suggests possible mechanisms for the diversification of Hox protein function.
authors: Centre National de la Recherche Scientifique, Aix-Marseille Université, CNRS UMR 7257, AFMB, 163 Avenue de Luminy, 13288 Marseille, France.
authors: Nicolas
authors: N
authors: Foos
authors: Centre National de la Recherche Scientifique, Aix-Marseille Université, CNRS UMR 7288, IBDM, Parc Scientifique de Luminy, Case 907, 13288 Marseille Cedex 09, France.
authors: Corinne
authors: C
authors: Maurel-Zaffran
authors: Centre National de la Recherche Scientifique, Aix-Marseille Université, CNRS UMR 7257, AFMB, 163 Avenue de Luminy, 13288 Marseille, France.
authors: María Jesús
authors: MJ
authors: Maté
authors: Centre National de la Recherche Scientifique, Aix-Marseille Université, CNRS UMR 7257, AFMB, 163 Avenue de Luminy, 13288 Marseille, France.
authors: Renaud
authors: R
authors: Vincentelli
authors: Centre National de la Recherche Scientifique, Aix-Marseille Université, CNRS UMR 7288, IBDM, Parc Scientifique de Luminy, Case 907, 13288 Marseille Cedex 09, France.
authors: Matthieu
authors: M
authors: Hainaut
authors: Centre National de la Recherche Scientifique, Aix-Marseille Université, CNRS UMR 7288, IBDM, Parc Scientifique de Luminy, Case 907, 13288 Marseille Cedex 09, France.
authors: Hélène
authors: H
authors: Berenger
authors: Centre National de la Recherche Scientifique, Aix-Marseille Université, CNRS UMR 7288, IBDM, Parc Scientifique de Luminy, Case 907, 13288 Marseille Cedex 09, France.
authors: Jacques
authors: J
authors: Pradel
authors: Centre National de la Recherche Scientifique, Aix-Marseille Université, CNRS UMR 7288, IBDM, Parc Scientifique de Luminy, Case 907, 13288 Marseille Cedex 09, France.
authors: Andrew J
authors: AJ
authors: Saurin
authors: Centre National de la Recherche Scientifique, Aix-Marseille Université, CNRS UMR 7257, AFMB, 163 Avenue de Luminy, 13288 Marseille, France. Electronic address: miguel.ortiz-lombardia@univ-amu.fr.
authors: Miguel
authors: M
authors: Ortiz-Lombardía
authors: Centre National de la Recherche Scientifique, Aix-Marseille Université, CNRS UMR 7288, IBDM, Parc Scientifique de Luminy, Case 907, 13288 Marseille Cedex 09, France. Electronic address: yacine.graba@univ-amu.fr.
authors: Yacine
authors: Y
authors: Graba
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003460:Crystallization; D004247:DNA / Q000378:metabolism*; D004330:Drosophila / Q000737:chemistry*; D029721:Drosophila Proteins / Q000737:chemistry* / Q000378:metabolism*; D024202:Electrophoretic Mobility Shift Assay; D018398:Homeodomain Proteins / Q000737:chemistry* / Q000378:metabolism*; D046911:Macromolecular Substances / Q000378:metabolism*; D008958:Models, Molecular; D015335:Molecular Probes / Q000235:genetics; D008969:Molecular Sequence Data; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D014157:Transcription Factors / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D046911:Macromolecular Substances; D015335:Molecular Probes; D014157:Transcription Factors; C066177:Ubx protein, Drosophila; C083405:exd protein, Drosophila; D004247:DNA