Date of Award
8-8-2017
Degree Type
Thesis
Degree Name
Master of Science (MS)
Department
Chemistry
First Advisor
Dr. Dabney Dixon
Second Advisor
Dr. Giovanni Gadda
Third Advisor
Dr. Donald Hamelberg
Abstract
Gram-positive pathogenic bacteria utilize cell-surface anchored proteins to bind and transport heme into the cell. These bacteria acquire iron from host proteins containing heme e.g., hemoglobin. Proteins like HmuT from Corynebacterium diphtheriae bind and help transport heme into the cell. Residues His136 and Tyr235 are utilized as the axial ligands, with a conserved Arg237 residue acting as the hydrogen bonding partner to the axial Tyr235. Similarly, Streptococcus pyogenes utilizes the cell anchored protein Shr to transfer heme into the cell. Shr-NEAT2 is hexacoordinated by two axial methionines and is prone to autoreduction where lysines are the most likely source of electrons. Lastly, PefR of Group A Streptococcus is a DNA transcription factor which regulates protein expression. Preliminary studies indicate a cysteine may coordinate the heme. A combination of UV-visible, resonance Raman, and magnetic circular dichroism spectroscopies shows these proteins play a crucial role heme transport and regulation.
DOI
https://doi.org/10.57709/10492697
Recommended Citation
Thompson, Stephanie, "Biophysical Heme Binding Studies of Corynebacterium diphtheriae and Streptococcus pyogenes." Thesis, Georgia State University, 2017.
doi: https://doi.org/10.57709/10492697