Date of Award
Chemistry and Biochemistry
John A. Latham
MftC is a radical S-adenosyl L-methionine (SAM) enzyme that catalyzes the first step in the production of mycofactocin. It is a ribosomally synthesized post-translationally modified (RiPP) redox cofactor shown to be essential for the survival of bacteria in the Mycobacterium genus in the presence of cholesterol as a carbon source and for the sequestration of ethanol. MftC catalyzes the C – terminal decarboxylation of tyrosine and the subsequent cross-linking of tyrosine to the penultimate valine on the precursor peptide MftA. The product formed out of the reaction is processed into mycofactocin in downstream processes. The bacteria in the Mycobacterium tuberculosis complex are pathogens that primarily affect mammalian lung systems and are subjected to oxygenated environments. It is also known that the bacteria in Mycobacterium species require highly aerobic conditions to survive. Radical SAM proteins require anaerobic conditions to catalyze reactions as their [4Fe-4S]2+ clusters are vulnerable to degradation by oxidation. MftC has to function when Mycobacterium species is present in oxygen rich environments such as lung tissue. Discerning the mechanism by which such an enzyme works in oxygen rich environments could provide insights into radical SAM chemistry. In order to investigate the effect of aerobic condition on the MftC reaction, here we seek to measure and demonstrate the change in efficacy of the MftC reaction after varying levels of oxygen exposure. We show that while the rate of the first part of the MftC reaction is slowed on exposure to oxygen, the second part of the reaction – the C – C cross-linking remains relatively unaffected on oxygen exposure.
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Govindarajan, Vishnu, "Sensitivity of Radical SAM Enzyme MftC to Molecular Oxygen" (2020). Electronic Theses and Dissertations. 1767.
Received from ProQuest