Purification and spectroscopic characterization of Ctb, a group III truncated hemoglobin implicated in oxygen metabolism in the food-borne pathogen Campylobacter jejuni.

ABSTRACT: Campylobacter jejuni is a food-borne bacterial pathogen that possesses two distinct hemoglobins, encoded by the ctb and cgb genes. The former codes for a truncated hemoglobin (Ctb) in group III, an assemblage of uncharacterized globins in diverse clinically and technologically significant bacteria. Here, we show that Ctb purifies as a monomeric, predominantly oxygenated species. Optical spectra of ferric, ferrous, O(2)- and CO-bound forms resemble those of other hemoglobins. However, resonance Raman analysis shows Ctb to have an atypical nu(Fe)(-)(CO) stretching mode at 514 cm(-)(1), compared to those of the other truncated hemoglobins that have been characterized so far. This implies unique roles in ligand stabilization for TyrB10, HisE7, and TrpG8, residues highly conserved within group

SUBMITTER: Wainwright LM 

PROVIDER: S-EPMC2528550 | biostudies-literature | 2006 May

REPOSITORIES: biostudies-literature