Significance of the chromosomal positions of the genes encoding Integration Host Factor and DNA gyrase in Salmonella.
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Pozdeev, German, Significance of the chromosomal positions of the genes encoding Integration Host Factor and DNA gyrase in Salmonella., Trinity College Dublin.School of Genetics & Microbiology, 2021Download Item:
Abstract:
In this thesis, two studies are described that built upon the idea of the chromosomal gene importance. In both studies Salmonella was used as a model organism. In the first study, ihfA and ihfB ? genes that encode nucleoid-associated protein IHF, have been repositioned in several ways, including an exchange of their open reading frames (OrfSwapihfA-ihfB) and creation of artificial operons. In the other study, gyrA and gyrB ? genes that encode an essential topoisomerase DNA gyrase, have been arranged in the gyrBA operon.
Multiple phenotypic tests highlighted Salmonella?s ability to successfully tolerate rearrangements of its genes. Minor alterations in the expression of SPI-1 and SPI-2 manifested in the ability of the strains to enter and survive in murine macrophages. The global DNA supercoiling in the gyrBA strain was found to be altered, indicating potential broad outcomes on the global gene expression.
The determination of the IhfA and IhfB protein levels by Western blotting in the WT and the OrfSwapihfA-ihfB strains led to the discovery that IhfB subunit is present in the WT at a concentration that is almost twice that of the IhfA subunit. This was confirmed by mass spectrometry that also showed that the pattern was swapped in the OrfSwapihfA-ihfB strain. It was determined that higher stability of ihfB mRNA is responsible for unequal production of IHF subunits.
Genes that encode DNA gyrase are located separately in gammaproteobacteria but in many other bacteria they are arranged in the operon. This puzzling inconsistency led to the comparative study of all the possible arrangements of these genes among bacteria. Four different groups of gyrA and gyrB arrangements were found that are based on 1 ? operonic or separate positioning, 2 ? conservation of the genetic environment 5' of gyrB. It was found that gyrB position is more conserved than that of gyrA.
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Science Foundation Ireland (SFI)
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https://tcdlocalportal.tcd.ie/pls/EnterApex/f?p=800:71:0::::P71_USERNAME:POZDEEVGDescription:
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Author: Pozdeev, German
Advisor:
Dorman, CharlesPublisher:
Trinity College Dublin. School of Genetics & Microbiology. Discipline of MicrobiologyType of material:
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