Characterizing the oligomeric structure and catalytic activity of the dihydroorotase and aspartate transcarbamoylase from the bacterium, <i>bacillus anthracis</i>

<p>Bacteremia refers to bacterial presence in the blood. Bacterial proliferation in the blood requires that the organism adapt its metabolism to available nutrients. Nucleotide precursors that could be used are present at low levels in the blood, and thus the invading bacteria must rely on <em>de novo</em> nucleotide biosynthesis for survival. The dihydroorotase domain is a key enzyme in pyrimidine biosynthesis and a promising drug target. The genes encoding the dihydroorotase (DHOase) and aspartate transcarbamoylase (ATCase) of <em>Bacillus anthracis</em> (<em>B. anthracis</em>) were cloned for expression in <em>Escherichia coli</em> (<em>E. coli</em>). The proteins were purified by affinity chromatography and the enzymatic activity was determined by enzyme assays. The data suggests that a physical and functional interaction exists. The activity of ATCase was increased by about 2 fold in the presence of an equimolar concentration of DHOase. An ATCase-DHOase complex was formed as judged by S-300 gel filtration chromatography and cross-linking methods. Moreover, orotate was found to be an effective inhibitor of the DHOase activity at nanomolar concentrations. These results bring us closer to understanding the structural organization of the pyrimidine pathway in the pathogenic <em>B. anthracis</em> bacterium and provide a lead in the design of drugs selective to the bacteria.</p>

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Open Access Thesis

Discipline thesis:degree_discipline

Chemistry

Year dc:date.available

2011

Author dc:creator

• Kankanala, Reshma

Contributors dc:contributor

• Dr. Hedeel Evans
• Dr. Steven Pernecky
• Dr. Deborah Heyl-Clegg

• oligomeric structure
• anthrax
• diydroorotase
• aspartate transcarbamoylase
• Chemistry

Repository record dc:identifier

https://commons.emich.edu/theses/339

OAI identifier oai:identifier

oai:commons.emich.edu:theses-1339