Scientific Publications by FDA Staff

J Inorg Biochem 2017 Feb;167:124-33

Characterization of the second conserved domain in the heme uptake protein HtaA from Corynebacterium diphtheriae.

Uluisik RC, Akbas N, Lukat-Rodgers GS, Adrian SA, Allen CE, Schmitt MP, Rodgers KR, Dixon DW

HtaA is a heme-binding protein that is part of the heme uptake system in Corynebacterium diphtheriae. HtaA contains two conserved regions (CR1 and CR2). It has been previously reported that both domains can bind heme; the CR2 domain binds hemoglobin more strongly than the CR1 domain. In this study, we report the biophysical characteristics of HtaA-CR2. UV-visible spectroscopy and resonance Raman experiments are consistent with this domain containing a single heme that is bound to the protein through an axial tyrosine ligand. Mutants of conserved tyrosine and histidine residues (Y361, H412, and Y490) have been studied. These mutants are isolated with very little heme (