title: Structure of peptide sex pheromone receptor PrgX and PrgX/pheromone complexes and regulation of conjugation in Enterococcus faecalis.
abstract: Many bacterial activities, including expression of virulence factors, horizontal genetic transfer, and production of antibiotics, are controlled by intercellular signaling using small molecules. To date, understanding of the molecular mechanisms of peptide-mediated cell-cell signaling has been limited by a dearth of published information about the molecular structures of the signaling components. Here, we present the molecular structure of PrgX, a DNA- and peptide-binding protein that regulates expression of the conjugative transfer genes of the Enterococcus faecalis plasmid pCF10 in response to an intercellular peptide pheromone signal. Comparison of the structures of PrgX and the PrgX/pheromone complex suggests that pheromone binding destabilizes PrgX tetramers, opening a 70-bp pCF10 DNA loop required for conjugation repression.
authors.affiliation: Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA.
authors.forename: Ke
authors.initials: K
authors.lastname: Shi
authors.forename: C Kent
authors.initials: CK
authors.lastname: Brown
authors.forename: Zu-Yi
authors.initials: ZY
authors.lastname: Gu
authors.forename: Briana K
authors.initials: BK
authors.lastname: Kozlowicz
authors.forename: Gary M
authors.initials: GM
authors.lastname: Dunny
authors.forename: Douglas H
authors.initials: DH
authors.lastname: Ohlendorf
authors.forename: Cathleen A
authors.initials: CA
authors.lastname: Earhart
mesh_terms: D001483:Base Sequence; D003227:Conjugation, Genetic / Q000502:physiology*; D018360:Crystallography, X-Ray; D004269:DNA, Bacterial / Q000737:chemistry / Q000378:metabolism; D019281:Dimerization; D013293:Enterococcus faecalis / Q000737:chemistry* / Q000502:physiology*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D020836:Protein Structure, Quaternary; D043563:Receptors, Pheromone / Q000737:chemistry* / Q000378:metabolism*; D012724:Sex Attractants / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D004269:DNA, Bacterial; D043563:Receptors, Pheromone; D012724:Sex Attractants