title: An RNA enhancer in a phage transcriptional antitermination complex functions as a structural switch.
abstract: Antitermination protein N regulates the transcriptional program of phage lambda through recognition of RNA enhancer elements. Binding of an arginine-rich peptide to one face of an RNA hairpin organizes the other, which in turn binds to the host antitermination complex. The induced RNA structure mimics a GNRA hairpin, an organizational element of rRNA and ribozymes. The two faces of the RNA, bridged by a sheared GA base pair, exhibit a specific pattern of base stacking and base flipping. This pattern is extended by stacking of an aromatic amino acid side chain with an unpaired adenine at the N-binding surface. Such extended stacking is coupled to induction of a specific internal RNA architecture and is blocked by RNA mutations associated in vivo with loss of transcriptional antitermination activity. Mimicry of a motif of RNA assembly by an RNA-protein complex permits its engagement within the antitermination machinery.
authors.affiliation: Department of Biochemistry and Molecular Biology and Center for Molecular Oncology, The University of Chicago, Illinois 60637-5419, USA.
authors.forename: L
authors.initials: L
authors.lastname: Su
authors.forename: J T
authors.initials: JT
authors.lastname: Radek
authors.forename: L A
authors.initials: LA
authors.lastname: Labeots
authors.forename: K
authors.initials: K
authors.lastname: Hallenga
authors.forename: P
authors.initials: P
authors.lastname: Hermanto
authors.forename: H
authors.initials: H
authors.lastname: Chen
authors.forename: S
authors.initials: S
authors.lastname: Nakagawa
authors.forename: M
authors.initials: M
authors.lastname: Zhao
authors.forename: S
authors.initials: S
authors.lastname: Kates
authors.forename: M A
authors.initials: MA
authors.lastname: Weiss
mesh_terms: D000595:Amino Acid Sequence; D017100:Bacteriophage P22 / Q000235:genetics / Q000378:metabolism; D010582:Bacteriophage lambda / Q000235:genetics* / Q000378:metabolism*; D001482:Base Composition; D001483:Base Sequence; D001665:Binding Sites; D004742:Enhancer Elements, Genetic; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D012367:RNA, Viral / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D015398:Signal Transduction; D054334:Viral Regulatory and Accessory Proteins / Q000378:metabolism
chemical_list: C059417:N protein, Bacteriophage lambda; D012367:RNA, Viral; D054334:Viral Regulatory and Accessory Proteins