Date of Award

2017

Document Type

Open Access Dissertation

Department

Chemistry and Biochemistry

Sub-Department

Chemistry

First Advisor

F. Wayne Outten

Abstract

Iron is an essential transition metal required by almost all organisms for use as a cofactor in many metabolic processes such as respiration and photosynthesis. Iron can be combined with elemental sulfur to form an iron-sulfur (Fe-S) cluster. In bacterial pathogens, Fe-S cluster cofactors carry out critical functions and the Fe-S cluster biogenesis pathway is essential for their survival. In E. coli, the Suf pathway assembles Fe-S clusters under conditions of iron starvation and oxidative stress. While some mechanistic details of the Fe-S cluster biogenesis have been well-characterized, the process of in vivo iron donation remains unclear. Iron storage proteins generally known as ferritins are capable of storing iron in a readily available and soluble form to serve as a reservoir of iron for metabolism. We are testing if these iron storage proteins can be in vivo iron donors for Suf Fe-S cluster assembly. Our results indicate that the bacterioferritin (Bfr) and DNA binding protein of starved cells (Dps) proteins may play roles in the in vivo donation to the Suf pathway. Our results also indicate the Ferritin A (FtnA) protein does not donate iron to this pathway. We also investigated what role the little characterized ferritin B protein may play in this iron donation. We found that the deletion of the FtnB and bacterioferritin proteins caused an inability for the strain to make Fe-S clusters. We therefore summarize that the three proteins: Bfr, Dps and FtnB donate iron to the Suf Fe-S cluster biogenesis pathway and have redundancy in their functions.

Included in

Chemistry Commons

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