This family is found within haem utilisation operons. It has a similar structure to that of Pfam:PF05171. Pfam:PF05171 usually occurs as a duplicated domain, but this domain occurs as a single domain and forms a dimer. The organisation of the dimer is very similar to that of the duplicated Pfam:PF05171 domains [1,2]. It binds haem via conserved histidines [2].

1: Crystal structure of AGR_C_4470p from Agrobacterium tumefaciens. Vorobiev SM, Neely H, Seetharaman J, Ma LC, Xiao R, Acton TB, Montelione GT, Tong L; Protein Sci. 2007;16:535-538. PMID:17322535

2: Structure and heme binding properties of Escherichia coli O157:H7 ChuX. Suits MD, Lang J, Pal GP, Couture M, Jia Z; Protein Sci. 2009;18:825-838. PMID:19319934