Translational stimulation: RNA sequence and structure requirements for binding of Com protein.
Translation of the bacteriophage Mu mom gene is positively regulated by the phage Com protein. We report here that purified Com protein specifically stimulates mom gene expression in vitro. Furthermore, Com is shown to bind a site in the mom translational initiation region (TIR) in a sequence-specific manner. In vitro RNA footprint experiments have been used to define the Com-binding site and to study mRNA secondary structure in the mom TIR. Com binding is shown to correlate with a conformational change in the mom TIR both in vivo and in vitro. The role of secondary structure was further examined by testing the effects of mutations in the TIR on translation and stimulation. The results support a model for translational stimulation in which Com binding induces a conformational change in the mom mRNA, thereby enhancing ribosome binding.
Wulczyn
F G
FG
Institut für Genbiologische Forschung Berlin GmbH, Federal Republic of Germany.
Kahmann
R
R
D010583:Bacteriophage mu / Q000235:genetics*; D001483:Base Sequence; D004926:Escherichia coli / Q000235:genetics; D015967:Gene Expression Regulation, Viral; D005814:Genes, Viral; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009690:Nucleic Acid Conformation; D009693:Nucleic Acid Hybridization; D009710:Nucleotide Mapping; D015345:Oligonucleotide Probes; D009876:Operon; D010957:Plasmids; D011485:Protein Binding; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics*; D012367:RNA, Viral / Q000235:genetics*; D014158:Transcription, Genetic; D014764:Viral Proteins / Q000378:metabolism*; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism
C068482:Com protein, Enterobacteria phage Mu; D015345:Oligonucleotide Probes; D012333:RNA, Messenger; D012367:RNA, Viral; D014764:Viral Proteins; D001616:beta-Galactosidase