Sensitivity of Radical SAM Enzyme MftC to Molecular Oxygen

<p>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 <em>Mycobacterium</em> 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 <em>Mycobacterium</em> tuberculosis complex are pathogens that primarily affect mammalian lung systems and are subjected to oxygenated environments. It is also known that the bacteria in <em>Mycobacterium</em> 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 <em>Mycobacterium</em> 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.</p>

Name thesis:degree_name

M. S.

Level thesis:degree_level

Masters Thesis

Year dc:date.available

2020

Author dc:creator

• Govindarajan, Vishnu

Contributors dc:contributor

• John A. Latham
• Scott Horowitz
• Erich Chapman
• Yan Qin

• MftC
• Mycobacterium
• Biological and Chemical Physics
• Physics

Statement dc:rights

• <p>Copyright is held by the author. User is responsible for all copyright compliance.</p>

Language dc:language

en

Repository record dc:identifier

https://digitalcommons.du.edu/etd/1767

OAI identifier oai:identifier

oai:digitalcommons.du.edu:etd-2763