This family of proteins is functionally uncharacterised. This protein is found in bacteria and archaea. Proteins in this family are about 200 amino acids in length. The structure of protein Swiss:Q63J81 from B. pseudomallei has been solved. This protein contains two domains, domain I (1:31, 46:81) is a helical domain, domain II (32:45,82-193) is a mainly beta protein with a beta barrel. According to crystal contacts the proteins probably functions as a dimer. The gene neighbourhood analysis suggests that this protein may be functionally related to rubrerythrin and ferredoxin. The wedge surface between the two domains might be functionally important. The fold of this protein could best be described as a circularly permuted C2-like fold (details derived from TOPSAN).