Ribosomal protein L4 of Escherichia coli: in vitro analysis of L4-mediated attenuation control.
Ribosomal protein L4 of Escherichia coli functions not only as a component of the ribosome but also as a regulatory factor inhibiting both transcription and translation of its own operon, the 11 gene S10 operon. L4-mediated transcription control results in premature termination of transcription within the 172 base S10 operon leader. This attenuation control can be reproduced in a purified transcription system containing RNA polymerase, but depends on the addition of transcription factor NusA. The NusA stimulation saturates at about 2-4 copies per RNA polymerase. The L4 effect plateaus at about 4 copies per RNA polymerase. The specific recognition sites on 23S rRNA and in the S10 leader for L4 binding are not yet known. However, we can demonstrate that a fragment of 23S rRNA containing the proximal 840 bases can eliminate in vitro L4-stimulated attenuation, and hence, contains the information sufficient for L4 binding to 23S rRNA.
Zengel
J M
JM
Department of Biology, University of Rochester, NY 14627.
Lindahl
L
L
D001483:Base Sequence; D001665:Binding Sites; D004252:DNA Mutational Analysis; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009876:Operon / Q000235:genetics*; D012336:RNA, Ribosomal, 16S / Q000378:metabolism; D012338:RNA, Ribosomal, 23S / Q000737:chemistry*; D012269:Ribosomal Proteins / Q000378:metabolism*; D014158:Transcription, Genetic
D012336:RNA, Ribosomal, 16S; D012338:RNA, Ribosomal, 23S; D012269:Ribosomal Proteins; C056368:ribosomal protein L4; D012321:DNA-Directed RNA Polymerases