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A Temperature-Sensitive Mutant Of Escherichia Coli Affected In The Alpha Subunit Of Rna Polymerase, Majid Mehrpouyan
A Temperature-Sensitive Mutant Of Escherichia Coli Affected In The Alpha Subunit Of Rna Polymerase, Majid Mehrpouyan
Electronic Theses and Dissertations
A temperature-sensitive mutant of Escherichia coli affected in the alpha subunit of RNA polymerase has been investigated. Gene mapping and complementation experiments placed the mutation to temperature-sensitivity within the alpha operon at 72 min on the bacterial chromosome. The rate of RNA synthesis in vivo and the accumulation of ribosomal RNA were significantly reduced in the mutant at 44$\sp\circ$C. The thermostability at 44$\sp\circ$C of the purified holoenzyme from mutant cells was about 20% of that of the normal enzyme. Assays with T7 DNA as a template showed that the fraction of active enzyme competent for transcription was reduced as a …
Purification And Characterization Of Enoyl-Acp Reductase From Euglena Gracilis, Margie M. Tucker
Purification And Characterization Of Enoyl-Acp Reductase From Euglena Gracilis, Margie M. Tucker
Electronic Theses and Dissertations
Enoyl-(acyl-carrier-protein) reductase was purified from the phytoflagellate Euglena gracilis. Its purification employed DEAE-Sephacel chromatography, Matrex Orange chromatography, and affinity chromatography using acyl carrier protein (ACP) covalently bound to Sepharose as the affinity ligand. Matrex Orange chromatography resolved two different enoyl-ACP reductases having different characteristics. Euglena gracilis appears to resemble higher plants in the possession of two isoforms of this enzyme. Antibodies specific for the cofactor binding site of NADP (H)-requiring dehydrogenases were obtained. They were isolated from a polyclonal population of antibodies directed against yeast glucose-6-phosphate dehydrogenase by affinity chromatography using chicken liver malic enzyme as the affinity ligand. The …