1887

Abstract

The promoter of the operon has been located by transcript mapping using primer extension with reverse transcriptase. The surrounding nucleotide sequence has features characteristic of promoters under stringent and growth-rate-dependent regulation, namely a GC-rich discriminator next to the −10 hexamer, an upstream AT-rich sequence (the UP element) and potential FIS-binding sites. Transcriptional activity of the promoter was examined using transcriptional fusions to placed at a single chromosomal location. Expression from was reduced under stringent conditions and varied with growth rate. Growth-rate control was independent of guanine-mediated repression. A fusion in which the GC-rich discriminator was mutated by insertion of an AT-rich oligonucleotide was used to demonstrate the importance of this region in control. Both stringent and growth-rate-dependent controls were abolished by the mutation. Other potential regulatory signals in the vicinity of the promoter are a operator (binding site for the PurR repressor), a operator, a DnaA-binding site and a CRP/FNR-binding sequence. The promoter lies back-to-back with the promoter for (exonuclease VII), the two promoters being separated by only 20 bp.

Loading

Article metrics loading...

/content/journal/micro/10.1099/00221287-142-9-2429
1996-09-01
2019-10-23
Loading full text...

Full text loading...

http://instance.metastore.ingenta.com/content/journal/micro/10.1099/00221287-142-9-2429
Loading
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error