Unusual organization of the ilvIH promoter of Escherichia coli

  title={Unusual organization of the ilvIH promoter of Escherichia coli},
  author={George W. Haughn and Charles H. Squires and Maurilio De Felice and Carmine T. Largo and Joseph M. Calvo},
  journal={Journal of Bacteriology},
  pages={186 - 198}
Analysis of plasmids containing ilvIH-galK fusions indicated that the Escherichia coli ilvIH promoter and sequences sufficient to cause leucine repression lie within 363 base pairs (bp) of ilvI. Experiments designed to locate the promoter and regulatory sequences more precisely gave the following results. The positions of the 5' endpoints of both unlabeled and pulse-labeled ilvIH mRNAs transcribed in vivo lie 30 bp upstream of ilvI. By contrast, the major in vitro RNA endpoints lie at positions… 
ilvIH Operon Expression in Escherichia coli Requires Lrp Binding to Two Distinct Regions of DNA
It is concluded that Lrp bound at downstream sites is necessary but not sufficient for promoter activation, and DNA at or upstream of position -160 is required for ilvIH promoter expression.
In vitro transcription from the Escherichia coli ilvIH promoter
It is established that Lrp acts directly to stimulate transcription from the ilvIH promoter, and it is suggested that the ilrp promoter is recognized by a sigma 70 RNA polymerase.
The ilvIH operon of Escherichia coli is positively regulated
Results indicate that the IHB protein is a positive regulator of ilvIH operon expression and propose that the designation lrp (leucine-responsive regulatory protein) be used in place of IHB.
In vivo footprinting analysis of Lrp binding to the ilvIH promoter region of Escherichia coli
Results suggest that leucine negatively affects ilvIH transcription because its interaction with Lrp reduces the efficiency of binding of the regulatory protein to the promoter region.
Mutations affecting the ability of Escherichia coli Lrp to bind DNA, activate transcription, or respond to leucine
This study suggests that Lrp has separate domains responsible for binding DNA, activating transcription, and responding to leucine, which is similar to other regulatory proteins in Escherichia coli.
A stereospecific alignment between the promoter and the cis-acting sequence is required for Lrp-dependent activation of ilvIH transcription in Escherichia coli.
An investigation of the mechanism of transcription activation of the ilvIH operon by Lrp indicated that a stereospecific alignment between the ilVIH promoter and the cis-acting sequence upstream of it is required for activation.
Escherichia coli Lrp (Leucine-Responsive Regulatory Protein) Does Not Directly Regulate Expression of theleu Operon Promoter
The simplest explanation of the observations of Lin et al. is that the known elevated leucine transport capacity of lrp strains leads to very high intracellular levels ofLeucine for strains grown with leucines, resulting in the superattenuation of leu operon expression.
Organization of Lrp‐binding sites upstream of ilvlH in Salmonella typhimurium
It is shown here that an Lrp‐like protein is also present in Salmonella typhimurium, which can bind both E. coli and S. typhIMurium ilvlH DNA and is compatible with that derived from a similar analysis ofE.
Absence of acetohydroxy acid synthase III in Salmonella typhimurium is due to early termination of translation within the ilvl gene
It is shown that the ilvH‐encoded subunit of Salmonella typhimurium is normally translated and the lack of activity is due to early termination of translation within the promoter‐proximal ilvl gene.


New M 13 vectors for cloning
  • Methods Enzymol .
  • 1983