Date of Award
2006
Degree Type
Thesis
Degree Name
Master of Science
Program
Biochemistry
Supervisor
Dr. Brian Shilton
Second Advisor
Dr. David Heinrichs
Abstract
The Staphylococcus aureus FhuD2 protein binds hydroxamate-type siderophores and delivers them to its cognate ABC transporter FhuBGC2. The present study intended to characterize the FhuD2 protein structurally using X-ray crystallography. FhuD2Δ43 crystals diffracted X-rays poorly and therefore to improve diffraction the protein was modified by reductive methylation of lysine residues. Crystals ofthe methylated protein diffracted to 2.2 Â. Molecular replacement techniques failed to find a solution for FhuD2Δ43 and therefore a heavy atom derivative of the protein was prepared and the structure of FhuD2Δ43 was solved using multi-wavelength anomalous dispersion (MAD). The FhuD2Δ43 structure was used as a model to solve the structure of a previously crystallized unmethylated FhuD2Δ24. The two structures are highly similar and differ in loop regions only, which shows that the methylation oflysine residues has a mild effect on the fold ofthe modified FhuD2Δ43.The Staphylococcus aureus FhuD2 protein binds hydroxamate-type siderophores and delivers them to its cognate ABC transporter FhuBGC2. The present study intended to characterize the FhuD2 protein structurally using X-ray crystallography. FhuD2Δ43 crystals diffracted X-rays poorly and therefore to improve diffraction the protein was modified by reductive methylation of lysine residues. Crystals ofthe methylated protein diffracted to 2.2 Â. Molecular replacement techniques failed to find a solution for FhuD2Δ43 and therefore a heavy atom derivative of the protein was prepared and the structure of FhuD2Δ43 was solved using multi-wavelength anomalous dispersion (MAD). The FhuD2Δ43 structure was used as a model to solve the structure of a previously crystallized unmethylated FhuD2Δ24. The two structures are highly similar and differ in loop regions only, which shows that the methylation of lysine residues has a mild effect on the fold of the modified FhuD2Δ43.The Staphylococcus aureus FhuD2 protein binds hydroxamate-type siderophores and delivers them to its cognate ABC transporter FhuBGC2. The present study intended to characterize the FhuD2 protein structurally using X-ray crystallography. FhuD2Δ43 crystals diffracted X-rays poorly and therefore to improve diffraction the protein was modified by reductive methylation of lysine residues. Crystals of the methylated protein diffracted to 2.2 Â. Molecular replacement techniques failed to find a solution for FhuD2Δ43 and therefore a heavy atom derivative of the protein was prepared and the structure of FhuD2Δ43 was solved using multi-wavelength anomalous dispersion (MAD). The FhuD2Δ43 structure was used as a model to solve the structure of a previously crystallized unmethylated FhuD2Δ24. The two structures are highly similar and differ in loop regions only, which shows that the methylation of lysine residues has a mild effect on the fold of the modified FhuD2Δ43.
Recommended Citation
Podkowa, Krzysztof J., "Crystallographic structure analysis of Staphylococcus aureus FhuD2" (2006). Digitized Theses. 4997.
https://ir.lib.uwo.ca/digitizedtheses/4997
