An RNA enhancer in a phage transcriptional antitermination complex functions as a structural switch.
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.
Su
L
L
Department of Biochemistry and Molecular Biology and Center for Molecular Oncology, The University of Chicago, Illinois 60637-5419, USA.
Radek
J T
JT
Labeots
L A
LA
Hallenga
K
K
Hermanto
P
P
Chen
H
H
Nakagawa
S
S
Zhao
M
M
Kates
S
S
Weiss
M A
MA
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
C059417:N protein, Bacteriophage lambda; D012367:RNA, Viral; D054334:Viral Regulatory and Accessory Proteins