The morphogenes are genes required for cell growth and division in <I>Escherichia coli. </I>The morphogenes are often grouped as clusters in different regions of the chromosome. The <I>mra </I>region, located at 2 minutes on the <I>E. coli</I> chromosome is the largest cluster of morphogenes. It contains sixteen open reading frames from which fourteen genes have been identified as encoding for proteins involved in either cell division or the biosynthesis of the cell wall. The organisation of the cluster appears to be complex with the genes tightly packed and often overlapping. Many of the genes appear to share promoters for their expression. However, several of these genes have been incompletely characterized. The predicted proteins encoded by <I>ftsW, </I>a cell division gene, and <I>mraY</I>, a gene required for murein synthesis, have not yet been identified. One of the aims of this study was to identify the peptides produced from <I>ftsW </I>an <I>mraY. </I>The mutant phenotypes of these genes are poorly characterized. At the time of this study there was no temperature sensitive <I>ftsW </I>allele and there was no mutant allele of <I>mraY. </I>In this study null mutants were made for both <I>ftsW</I> and <I>mraY</I>. This allowed a more accurate characterization of their roles in cell division and cell growth, respectively. The isolation of the mutants allowed studies on their complementation. The promoter regions required for the independent expression of <I>ftsW </I>and <I>mraY</I> were then identified. The close proximity of genes in the <I>mra</I> region, the presence of overlaps and the sharing of promoters has provoked speculation that several of these genes may be translationally coupled. A previous study on three genes of the <I>mra</I> cluster revealed no translational coupling between the three genes but showed differences in the efficiency of translation of each gene product.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:641862 |
| Date | January 1995 |
| Creators | Boyle, David S. |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/12569 |
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