Independent ligand-induced folding of the RNA-binding domain and two functionally distinct antitermination regions in the phage lambda N protein.
The transcriptional antitermination protein N of bacteriophage lambda binds the boxB component of the RNA enhancer nut (boxA + boxB) and the E. coli elongation factor NusA. Efficient antitermination by N requires an RNA-binding domain (amino acids 1-22) and two activating regions for antitermination: a newly identified NusA-binding region (amino acids 34-47) that suppresses NusA's enhancement of termination, and a carboxy-terminal region (amino acids 73-107) that interacts directly with RNA polymerase. Heteronuclear magnetic resonance experiments demonstrate that N is a disordered protein. Interaction with boxB RNA induces only the RNA-binding domain of N to adopt a folded conformation, while the activating regions of the protein remain disordered in the absence of their target proteins.
Mogridge
J
J
Banting and Best Department of Medical Research, Department of Molecular and Medical Genetics, University of Toronto, Ontario, Canada.
Legault
P
P
Li
J
J
Van Oene
M D
MD
Kay
L E
LE
Greenblatt
J
J
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D010582:Bacteriophage lambda / Q000737:chemistry* / Q000201:enzymology / Q000235:genetics*; D001665:Binding Sites / Q000502:physiology; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D004742:Enhancer Elements, Genetic / Q000502:physiology; D029968:Escherichia coli Proteins; D015967:Gene Expression Regulation, Viral; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D010445:Peptide Elongation Factors; D010446:Peptide Fragments / Q000378:metabolism; D017434:Protein Structure, Tertiary; D012367:RNA, Viral / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012045:Regulatory Sequences, Nucleic Acid; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism; D035602:Transcriptional Elongation Factors; D054334:Viral Regulatory and Accessory Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D008024:Ligands; C059417:N protein, Bacteriophage lambda; D010445:Peptide Elongation Factors; D010446:Peptide Fragments; D012367:RNA, Viral; D014157:Transcription Factors; D035602:Transcriptional Elongation Factors; D054334:Viral Regulatory and Accessory Proteins; C068727:nusA protein, E coli; D012321:DNA-Directed RNA Polymerases