Corynebacterium diphtheriae is a Gram-positive, pathogenic bacterium. Pathogenic bacteria require iron as a key nutrient for survival. C. diphtheriae utilizes a direct heme uptake system in which the heme binds to a receptor protein that transfers the heme along the pathway to an ABC transporter, which facilitates the transfer of heme into the bacterial cell. This heme uptake pathway is encoded by the hmu and cht gene loci, which includes the genes for the surface-anchored proteins HtaB and ChtB. HtaB is proposed to have a function in transporting the heme obtained by HtaA to HmuT. ChtB is proposed to have a similar function to that of HtaB. Bioinformatics analysis shows that both HtaB and ChtB contain conserved tyrosine and histidine residues that are consistent with that of HtaA domains. A combination of UV-visible, circular dichroism, resonance Raman, and fluorescence spectroscopy have been used to characterize these proteins further.