The four essential cell division genes <i>ftsQ, ftsA, ftsZ</i>, and <i>envA</i> are arranged sequentially within a large cluster of genes required for cell envelope growth and form. The bacteriophage λJFL100 carries the 1.8 kilobase <i>Eco</i>R1-<i>Hin</i>dIII chromosomal restriction fragment which spans the <i>ftsQ</i> and part of <i>ftsA</i> coding sequences. This fragment contains at least two promoters; one within <i>ftsQ</i> is required for the expression of <i>ftsA</i> and one within <i>ftsA</i> is required for expression of <i>ftsZ</i>. The <i>fts</i> fragment is cloned upstream of a <i>lacZ</i> gene so that transcription originating from within the fragment leads to the production of β-galactosidase. Expression from the <i>fts</i> promoters in cells lysogenic for the phage is shown to be derepressed in the absence of FtsA protein. The results presented here suggest that transcription from these promoters is linked to the cell's periodic requirement for FtsA protein during septum formation. The exact positions of the promoters within the group are not yet known although their approximate locations have been determined by promoter assay and sequence analysis. An attempt has been made to define the position of the <i>ftsA</i> promoter more precisely by <i>in-vitro</i> transcription from short, defined templates and by the sequential deletion of <i>ftsQ</i>. Serial deletion through <i>ftsQ</i> has revealed what appears to be a complex upstream regulatory region, reminiscent of a eukaryotic enhancer element, which influences the expression of <i>ftsA</i>. A model is presented for the transcriptional control of <i>ftsA</i> expression.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:649496 |
| Date | January 1988 |
| Creators | Dewar, Susan J. |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/13636 |
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