Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 171-191).

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 183-192). Also available on the Internet.

DRMT4 (Drosophila Arginine MethylTransferase 4) is an arginine methyltransferase in Drosophila (Boulanger et al. 2004). It shows the highest identities with mammalian PRMT4/CARM1 (Protein Arginine MethylTransferase 4) (59% identity, 75% similarity). HPLC analysis demonstrated that DRMT4 belongs to the type I class of methyltransferases (Boulanger et al. 2004), meaning that DRMT4 catalyzes asymmetrical dimethylarginine formation. A polyclonal antibody against DRMT4 was generated and used to study DRMT4 expression using western blots and immunostainings. In order to study DRMT4 function in Drosophila using genetic methods, we created three kinds of DRMT4 transgenes: a genomic DRMT4 under its own control, a genomic DRMT4-GFP fusion gene and a cDNA DRMT4 under UAS control. We investigated DRMT4 localization in wild type flies using the DRMT4-GFP transgenic line and immunostaining.

Thesis (Ph. D.)--Illinois State University, 2000. / Title from title page screen, viewed May 11, 2006. Dissertation Committee: David Borst (chair), Anthony Otsuka, Radheshyam Jayaswal, Paul Garris, David Williams. Includes bibliographical references (leaves 130-135) and abstract. Also available in print.

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 183-192). Also available on the Internet.

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This document only includes an excerpt of the corresponding thesis or dissertation. To request a digital scan of the full text, please contact the Ruth Lilly Medical Library's Interlibrary Loan Department (rlmlill@iu.edu).

<p> The extensive;: use of antibiotics in the clinic, veterinary medicine, and agricultures has imposed an immense selective pressure for the emergence of antibiotic resistant bacteria In order to maintain the upper hand against pathogenic bacteria, we must constantly seek new antimicrobials. Most antibiotics used in the clinic were discovered as natural products or are derivatives thereof. Therefore, we must seek means of increasing the chemical diversity of natural products in our quest for new antibiotics. Herein, we investigate methyltransferases as agents to increase chemical diversity. More specificity, we have performed biochemical studies on a tetracycline and a glycopeptide methyltransferase. </p> <p> In our studies of the putative tetracycline N-methyltransferase OxyT, we determined the conditions required to overexpress the protein in an E. coli host. Subsequently, using purified protein we examined substrate specificity using commercially available compounds. However, we were unable to detect methylation of the compounds tested and therefore we made an effort to secure a biologically relevant substrate by insertionally inactivating the oxyT gene in S. rimosus but were unsuccessful. </p> <p> In our studies of the glycopeptide N-methyltransferase MtfA, we examined the biochemical activity of this enzyme on the glycopeptide desulfo-A47934. We purified desulfo-A47934 as a fermentation product of S. toyocaensis ΔstaL and determined an extinction co-efficient of 4200 Lmol^-1cm^-1. Furthermore, based on a crystal structure of MtfA we biochemically characterized the enzyme and its four mutants Y32F, E144A, H228A, and R230A to study residues involved in substrate binding and catalysis. We demonstrated that these mutations did not alter quaternary protein structure but did lead to a significant decrease in enzyme activity as compared to the wild-type enzyme. </p> / Thesis / Master of Science (MSc)

Diss. (sammanfattning) Linköping : Linköpings universitet, 2005. / Härtill 4 uppsatser.

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