Sequence-specific recognition of RNA hairpins by bacteriophage antiterminators requires a conserved arginine-rich motif.
We have dissected the protein and nucleic acid determinants that direct a group of transcriptional antiterminators to their specific target operons. These antiterminators, the N gene products of phages lambda, 21, and P22, function solely with their respective recognition sites, nut, to modify RNA polymerase to a termination-resistant form. We demonstrate that a unique hairpin sequence within each nut site, called boxB, confers genome specificity by interacting with a small amino-terminal domain of the cognate N protein. This interaction is dependent upon an arginine-rich subdomain, which is conserved not only among the N proteins but also in many RNA binding proteins from ribosomes and RNA virus capsids. Notably, this motif constitutes an essential domain of the HIV protein Tat whose function as a trans-activator requires a specific hairpin sequence.
Lazinski
D
D
Department of Microbiology, University of Connecticut Health Center, Farmington 06032.
Grzadzielska
E
E
Das
A
A
D000595:Amino Acid Sequence; D001120:Arginine / Q000235:genetics* / Q000502:physiology; D010582:Bacteriophage lambda / Q000235:genetics* / Q000502:physiology; D001483:Base Sequence; D003001:Cloning, Molecular; D005809:Genes, Regulator; D005814:Genes, Viral; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010957:Plasmids; D011487:Protein Conformation; D012313:RNA / Q000235:genetics*; D013728:Terminator Regions, Genetic; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*; D014764:Viral Proteins / Q000235:genetics*
D014157:Transcription Factors; D014764:Viral Proteins; D012313:RNA; D001120:Arginine