title: Structure of theEscherichia coliProQ RNA-binding protein.
abstract: The protein ProQ has recently been identified as a global small noncoding RNA-binding protein inSalmonella, and a similar role is anticipated for its numerous homologs in divergent bacterial species. We report the solution structure ofEscherichia coliProQ, revealing an N-terminal FinO-like domain, a C-terminal domain that unexpectedly has a Tudor domain fold commonly found in eukaryotes, and an elongated bridging intradomain linker that is flexible but nonetheless incompressible. Structure-based sequence analysis suggests that the Tudor domain was acquired through horizontal gene transfer and gene fusion to the ancestral FinO-like domain. Through a combination of biochemical and biophysical approaches, we have mapped putative RNA-binding surfaces on all three domains of ProQ and modeled the protein's conformation in theapoand RNA-bound forms. Taken together, these data suggest how the FinO, Tudor, and linker domains of ProQ cooperate to recognize complex RNA structures and serve to promote RNA-mediated regulation.
authors.affiliation: Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, United Kingdom.
authors.forename: Grecia M
authors.initials: GM
authors.lastname: Gonzalez
authors.affiliation: Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, United Kingdom.
authors.forename: Steven W
authors.initials: SW
authors.lastname: Hardwick
authors.affiliation: MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom.
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Maslen
authors.affiliation: MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom.
authors.forename: J Mark
authors.initials: JM
authors.lastname: Skehel
authors.affiliation: Department of Cell and Molecular Biology, Biomedical Center, Uppsala University, 75124 Uppsala, Sweden.
authors.forename: Erik
authors.initials: E
authors.lastname: Holmqvist
authors.affiliation: RNA Biology Group, Institute of Molecular Infection Biology, University of Würzburg, D-97080 Wurzburg, Germany.|Helmholtz Institute for RNA-based Infection Research (HIRI), University of Würzburg, D-97080 Wurzburg, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Vogel
authors.affiliation: European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton, Cambridge CB10 1SD, United Kingdom.
authors.forename: Alex
authors.initials: A
authors.lastname: Bateman
authors.affiliation: Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, United Kingdom.
authors.forename: Ben F
authors.initials: BF
authors.lastname: Luisi
authors.affiliation: Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, United Kingdom.
authors.forename: R William
authors.initials: RW
authors.lastname: Broadhurst
mesh_terms: D020413:3' Untranslated Regions; D001665:Binding Sites; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000378:metabolism; D035001:Host Factor 1 Protein / Q000378:metabolism; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D000072417:Protein Domains; D016601:RNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism
chemical_list: D020413:3' Untranslated Regions; D029968:Escherichia coli Proteins; C087373:Hfq protein, E coli; D035001:Host Factor 1 Protein; C118132:ProQ protein, E coli; D016601:RNA-Binding Proteins
keywords: FinO; ProQ; RNA chaperone; protein–RNA interactions; regulatory RNA; riboregulation