Item – Theses Canada

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OCLC number
56631254
Link(s) to full text
LAC copy
LAC copy
Author
Stokell, David John,1975-
Title
Structural-functional analysis of unique features of Escherichia coli citrate synthase using in vitro mutagenesis.
Degree
M. Sc. -- University of Manitoba, 2002
Publisher
Ottawa : National Library of Canada = Bibliothèque nationale du Canada, [2004]
Description
2 microfiches.
Notes
Includes bibliographical references.
Abstract
Gram negative bacteria may be distinguished from other prokaryotes and eukaryotes by the fact that they contain a citrate synthase (CS), designated Type II, that has a hexameric subunit structure, and is allosterically inhibited by NADH and activated by KCl. Citrate synthases from gram positive bacteria, archeaeobacteria and eucaryotes are classified as Type I and are non-allosteric dimers. Recently, a crystal structure has been obtained for CS from ' Escherichia coli', the first structure for a Type II enzyme. A crystal structure for NADH bound to an 'E. coli' CS variant protein, F383A, has also been obtained. These structures show a number of features that are absent from Type I enzymes: an NADH binding site; a central cationic pore lined with 18 arginine residues (three from each of the six subunits); and a novel N-terminal domain. In this Thesis, site-directed mutagenesis has been used to investigate the functions of these structural features. To investigate the NADH binding site, nine residues, whose side chains appeared to be positioned so as to form hydrogen bonds to the bound NADH, were chosen for mutagenesis. (Abstract shortened by UMI.)
ISBN
0612800458
9780612800458