The ogt gene encodes an O\(^6\)-alkylguanine DNA alkyltransferase, which is reported to repair DNA against methylation damage caused by reactive nitrogen species, which are generated during an anaerobic respiration in a presence of nitrate. This study examined transcription activation by NarL at the ogt promoter using biochemical techniques with various semi-synthetic ogt promoters. The ogt promoter has two crucial DNA sites for NarL dimers at positions -78.5 and -45.5 relative to the transcript start site. An interaction between NarL and αCTD was investigated using site-specific mutagenesis. Locations and orientations of NarL and RNA polymerase in the transcript initiation complex were also confirmed in this study. It was found that NarL, at position 45.5, is located on the different DNA helical face from αCTD, which binds to the minor groove immediately upstream the -35 element. This unrecognized promoter architecture allows residue 273 of αCTD to interact with residue 178 of NarL.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:577871 |
| Date | January 2013 |
| Creators | Ruanto, Patcharawarin |
| Publisher | University of Birmingham |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://etheses.bham.ac.uk//id/eprint/4480/ |
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