heme utilization protein ChuX and similar proteins
This family contains ChuX, a member of the conserved heme utilization operon from pathogenic E. coli, and similar proteins, which include ChuS, HutX, HuvX, HugX, and ShuX in proteobacteria, among others. It forms a dimer which displays a very similar fold and organization to the monomeric structure of other heme utilization proteins such as HemS, ChuS, HmuS, PhuS; these latter occurring as duplicated domains. They all bind heme via a key conserved histidine. The genes encoded within these heme utilization operons enable the effective uptake and utilization of heme as an iron source in pathogenic microorganisms to enable multiplication and survival within hosts they invade.