Attenuation in the rph-pyrE operon of Escherichia coli and processing of the dicistronic mRNA.
We have substituted on a plasmid the native promoter of the Escherichia coli rph-pyrE operon with an inducible transcription-initiation signal. The plasmid was used to study the mRNA chains derived from the operon at different intracellular concentrations of UTP and as a function of time following induction of transcription. The results showed that dicistronic rph-pyrE mRNA was formed when the UTP pool was low, and that a monocistronic rph mRNa was the major transcription product in high-UTP pools, thus supporting an UTP-controlled attenuation mechanism for regulation of pyrE gene expression. However, the dicistronic rph-pyrE transcript was rapidly processed into two monocistronic mRNA units, and a cleavage site was mapped near the attenuator in the intercistronic region, close to the site where transcription was terminated in high-UTP pools. Furthermore, the major 3' end of the pyrE mRNA was mapped near a palindromic structure of similarity to the family of repetitive extragenic palindromic sequences, 35 nucleotide residues after stop codon of the pryE gene.
Andersen
J T
JT
Institute of Biological Chemistry B, University of Copenhagen, Denmark.
Poulsen
P
P
Jensen
K F
KF
D001483:Base Sequence; D015152:Blotting, Northern; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D009876:Operon; D009962:Orotate Phosphoribosyltransferase / Q000096:biosynthesis / Q000235:genetics*; D010957:Plasmids; D011401:Promoter Regions, Genetic; D012323:RNA Processing, Post-Transcriptional; D012329:RNA, Bacterial / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D013728:Terminator Regions, Genetic; D014158:Transcription, Genetic
D012329:RNA, Bacterial; D012333:RNA, Messenger; D009962:Orotate Phosphoribosyltransferase