Discipline: Biological Sciences
Subcategory: Biochemistry (not Cell and Molecular Biology and Genetics)
Ashlee Elizabeth Williams - Dillard University
Co-Author(s): Limei Zhang. Ph.D., University of Nebraska-Lincoln, Lincoln, Nebraska; Daisy Beltran, University of Nebraska-Lincoln, Lincoln Nebraska
WhiB7 is a redox-sensitive transcriptional activator. It belongs to a unique family of iron-sulfur proteins, named the WhiB family, well conserved in actinomycetes and found only in Actinobacteria. Previous studies indicate that WhiB7 is critical for the activation of unique systems that confers resistance to multiple antibiotics with distinct structures and it is linked to redox homeostasis (Burian, Nucleic Acids Res., 2013). A thorough understanding of the role and the underlying mechanism of action of WhiB7 is very important considering the medical and economic significance of many actinomycetes. The goal of this study is to provide structural basis of the molecular mechanisms of WhiB7 in antibiotic resistance and redox homeostasis. During this research, the whiB7 homologs from several actinomycetes (Streptomyces coelicolor, Mycobacterium tuberculosis and Mycobacterium smegmatis) will be cloned into the expression vectors for over-expression in E. coli. The purified WhiB7 proteins will be used for crystallization screening and subsequence structural characterization by X-ray crystallography in the future. The stability of the WhiB7 homologs and their reaction with different redox-active molecules and thiol-based molecules will also be examined by UV-Vis spectroscopy, to gain insights into how protein folding determines the stability and reactivity of iron-sulfur clusters in these proteins. The structural information obtained will help to elucidate the molecular mechanism of whiB7 in the redox stress response and antibiotic resistance.
Not SubmittedFunder Acknowledgement(s): National Science Foundation (NSF)
Faculty Advisor: Ruby Broadway, rbroadway@dillard.edu@dillard.edu
Role: Under the supervision of my mentor and PI, the research was completed by me.