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Degree Name
MS (Master of Science)
Program
Biology
Date of Award
12-2014
Committee Chair or Co-Chairs
Cecilia McIntosh
Committee Members
Shivakumar Devaiah, Aruna Kilaru
Abstract
Flavonoids are plant secondary metabolites that have significant biochemical and physiological roles. Biosynthesis of these compounds involves several modifications, most predominantly glucosylation, which is catalyzed by glucosyltransferases (GTs). A signature amino acid sequence, the PSPG box, is used to identify putative clones and has been shown to be involved in UDP-glucose binding. Site-directed mutagenesis is used to answer questions regarding the structure and function of this family of enzymes, particularly what allows some GTs to be more selective towards some substrates than others. The grapefruit (Citrus paradisi) flavonol-3-O-glucosyltransferase (CpF3GT) is specific for flavonol substrates and will not glucosylate anthocyanidins. Comparison of the CpF3GT sequence with that of Vitis vinifera GT, which glucosylates both flavonols and anthocyanidins, provided the basis for the amino acid substitution of proline 145, alanine 374, and alanine 375 in CpF3GT to threonine, aspartate, and glycine, respectively, to test the affect on GT’s affinity for flavonoid substrates.
Document Type
Thesis - restricted
Recommended Citation
Khaja, Sara, "Site-Directed Mutagenesis in Citrus paradisi Flavonol-Specific 3-O-Glucosyltransferase" (2014). Electronic Theses and Dissertations. Paper 2453. https://dc.etsu.edu/etd/2453
Copyright
Copyright by the authors.