Date of Award


Degree Type


Degree Name

Master of Science (MS)



First Advisor

Dabney W. Dixon - Chair

Second Advisor

Kathy Grant

Third Advisor

Zehava Eichenbaum


The bacterium Streptococcus pyogenes requires heme, which is taken up via an ABC transporter. An understanding of this pathway may result in new approaches to antibacterial agents. Both SiaA and NEAT2 (NEAr Transporter 2) are proteins involved in heme binding. One of the axial ligands of SiaA, His 229, was purified to study how mutagenesis affects heme binding. UV-visible studies showed a small band at 420 nm with respect to the protein band at 288 nm which probably indicates that heme was lost easily from this mutant. We have also worked to optimize the yield of Shr-NEAT2 by changing different variables. For each of the batches, the yield of holoNEAT2 was calculated by UV-visible spectroscopy. Increasing oxygen during growth did not improve holoNEAT2 yield. On the other hand, lower temperature, decrease in time after induction, and addition of ALA all increased the protein production.