Honors Program


Date of this Version

Spring 2022

Document Type



Wong, H-X., Zhang, J., & Zhang, L. Characterization of the DUF4193 Family Protein Rv2699c in Mycobacteria. Undergraduate Honors Thesis. University of Nebraska-Lincoln. 2022.


Copyright Huey-Xian Wong, LiMei Zhang, Jing Zhang 2022.


The epidemic of tuberculosis caused by the bacterial pathogen Mycobacterium tuberculosis (Mtb) continues to be a leading cause of death from a single bacterial infectious agent today. Identification and characterization of the proteins responsible for the pathogen’s highly adaptive stress responses are of the foremost interest for developing new drugs combating the Mtb epidemic. Towards the goal, this thesis work focuses on Rv2699c in Mtb, an uncharacterized protein belonging to the DUF4193 family and reportedly responsive to the redox stress in Mtb. Members of the DUF4193 family are highly conserved in Actinobacteria, including mycobacteria, featuring four conserved cysteines and a histidine, and possess a CXXXXH motif. Structural modeling suggests that the four conserved cysteines clustered in a tetrahedral orientation are suitable for zinc (Zn) binding. By using site-directed mutagenesis, X-ray fluorescence spectroscopy, and total metal analysis, we confirm that Rv2699c coordinates a Zn ion through its highly conserved cysteines. Results from this study will improve the understanding of the potential role of Rv2699c in the survival and stress response in Mtb and, more broadly, in Actinobacteria.