Date of Award
8-8-2008
Degree Type
Thesis
First Advisor
Dr. Dabney Dixon
Second Advisor
Dr. Robert Sattelmeyer
Abstract
Many pathogenic bacteria use their iron acquisition mechanisms to live inside hosts. Streptococcus pyogenes is a pathogenic bacterium that uses streptococcal iron acquisition ABC transporter to obtain heme. SiaA (HtsA, spy1795), a lipoprotein located on the cell surface, serves as a heme binding protein. To understand the iron-uptake mechanism, histidine 229, one of the two proposed axial ligands in SiaA, was mutated to alanine. SiaA H229A was expressed in E. coli, lysed by French Press, and purified by fast protein liquid chromatography (FPLC). SDS-PAGE indicated that pure protein was isolated. Nickel affinity FPLC gave purer H229A when 0.5 M imidazole was added to the binding buffer. Overall, histidine 229 is likely to be an axial ligand in wild type SiaA, as shown by the fact the mutant readily lost heme as evidenced by UV-vis spectra.
DOI
https://doi.org/10.57709/1062201
Recommended Citation
Nguyen, Nhung Phuong, "Axial Ligand Mutant: H229A." Thesis, Georgia State University, 2008.
doi: https://doi.org/10.57709/1062201