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Dna Wrapping And The Nature Of Interaction Between E. Coli Rna Polymerase And Promoter Dna., Parisa Jazbi
Dna Wrapping And The Nature Of Interaction Between E. Coli Rna Polymerase And Promoter Dna., Parisa Jazbi
LSU Historical Dissertations and Theses
Regulation of transcription most often occurs at the stage of initiation. RNA polymerase binding to the transcription start site, the promoter, is influenced by many nucleotide sequence elements. The predominant recognition sequences are those bound by the $\sigma$ subunit of RNA polymerase located at $-$10 and $-$35 relative to initiation site of most promoters. Another element involved in this regulation is intrinsic DNA curvature. In this study, the contribution of intrinsically curved DNA immediately upstream of the promoter to the interaction between Escherichia coli RNA polymerase and this DNA was examined. DNase I footprinting analysis confirmed that RNA polymerase wraps …
Cloning, Sequencing And Regulation Of The Rhodobacter Capsulatus Hemh Gene., Ekaterina Vladislavova Kanazireva
Cloning, Sequencing And Regulation Of The Rhodobacter Capsulatus Hemh Gene., Ekaterina Vladislavova Kanazireva
LSU Historical Dissertations and Theses
Rhodobacter capsulatus, a purple non-sulfur photosynthetic bacterium, synthesizes four tetrapyrrole end products: heme, bacteriochlorophyll, siroheme and vitamin B$\sb{12}$ via the common tetrapyrrole biosynthetic pathway. The biosynthesis of tetrapyrroles in R. capsulatus is a complex and precisely controlled process which has been under extensive investigation. In order to study the regulation of tetrapyrrole biosynthesis, the R. capsulatus hemH gene was cloned by complementation of an E. coli $\Delta hemH$ mutant and sequenced. The enzyme ferrochelatase, encoded by the hemH gene, catalyzes the insertion of ferrous iron into protoporphyrin IX, thus producing heme. The consensus ferrochelatase signature sequence was found in the …
Cloning And Expression Of Capsid Proteins Of Hepatitis A Virus In Escherichia Coli., Lingaiah Chandrashekar
Cloning And Expression Of Capsid Proteins Of Hepatitis A Virus In Escherichia Coli., Lingaiah Chandrashekar
LSU Historical Dissertations and Theses
Hepatitis A virus (HAV), the causative agent of food and water borne acute hepatitis worldwide, is very difficult and expensive to propagate in tissue culture. Large scale production of HAV proteins in E. coli by recombinant DNA techniques would be invaluable for antisera production, biochemical analyses and in developing sensitive diagnostic tests. Therefore, PCR amplified DNA fragments encoding the HAV capsid proteins were cloned individually into prokaryotic expression vectors for production of either recombinant fusion or non-fusion proteins. Cloning and expression of HAV capsid genes, which induced toxic effects in certain host E. coli, was tolerated better by protease-deficient host …
The Polysaccharide Capsule Of Vibrio Vulnificus: Virulence, Transposon Mutagenesis, And The Identification Of An Essential Gene., Amy Buscher Zuppardo
The Polysaccharide Capsule Of Vibrio Vulnificus: Virulence, Transposon Mutagenesis, And The Identification Of An Essential Gene., Amy Buscher Zuppardo
LSU Historical Dissertations and Theses
The extracellular capsule polysaccharide (CPS) of Vibrio vulnificus is a primary virulence factor which allows survival of the bacteria in the human host. To study the genes involved in the production of the polysaccharide capsule, 23 mutants were generated that lost their ability to produce CPS due to the insertion of a mini-transposon into the genome of the encapsulated clinical strain V. vulnificus 1003 (O). The mutants were examined by Southern blot analysis to ensure the transposon had inserted only once in the chromosome. Exoenzymes, which are believed to contribute to the virulence of the organism, produced by all 23 …
The Radioresistance Of Deinococcus Radiodurans., Valerie Mattimore
The Radioresistance Of Deinococcus Radiodurans., Valerie Mattimore
LSU Historical Dissertations and Theses
Deinococcus radiodurans is a remarkably ionizing radiation resistant bacterium. As a vegetative cell it is capable of withstanding 5,000 Gy ionizing radiation without evidence of death or mutation. D. radiodurans survives irradiation by repairing DNA damage via an extremely efficient DNA repair system. However, this DNA repair system has not been completely defined. In addition, the selective process allowing the evolution of high level radioresistance has remained a question. This dissertation bolsters the understanding of the DNA repair system of D. radiodurans by characterizing a collection of ionizing radiation sensitive (IRS) mutants. The level of radioresistance is quantified and transformation …