title: Structure of the trp RNA-binding attenuation protein, TRAP, bound to RNA.
abstract: The trp RNA-binding attenuation protein (TRAP) regulates expression of the tryptophan biosynthetic genes of several bacilli by binding single-stranded RNA. The binding sequence is composed of eleven triplet repeats, predominantly GAG, separated by two or three non-conserved nucleotides. Here we present the crystal structure of a complex of TRAP and a 53-base single-stranded RNA containing eleven GAG triplets, revealing that each triplet is accommodated in a binding pocket formed by beta-strands. In the complex, the RNA has an extended structure without any base-pairing and binds to the protein mostly by specific protein-base interactions. Eleven binding pockets on the circular TRAP 11-mer form a belt with a diameter of about 80 A. This simple but elegant mechanism of arresting the RNA segment by encircling it around a protein disk is applicable to both transcription, when TRAP binds the nascent RNA, and to translation, when TRAP binds the same sequence within a non-coding leader region of the messenger RNA.
authors.affiliation: York Structural Biology Laboratory, Department of Chemistry, University of York, UK. fred@yorvic.york.ac.uk
authors.forename: A A
authors.initials: AA
authors.lastname: Antson
authors.forename: E J
authors.initials: EJ
authors.lastname: Dodson
authors.forename: G
authors.initials: G
authors.lastname: Dodson
authors.forename: R B
authors.initials: RB
authors.lastname: Greaves
authors.forename: X
authors.initials: X
authors.lastname: Chen
authors.forename: P
authors.initials: P
authors.lastname: Gollnick
mesh_terms: D001426:Bacterial Proteins; D001483:Base Sequence; D018360:Crystallography, X-Ray; D004926:Escherichia coli; D001411:Geobacillus stearothermophilus / Q000737:chemistry / Q000235:genetics; D046911:Macromolecular Substances; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D011487:Protein Conformation; D012313:RNA / Q000737:chemistry* / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D046911:Macromolecular Substances; C079092:MtrB protein, Bacteria; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins; D014157:Transcription Factors; D012313:RNA