This is a family of 3-deoxy-D-manno-oct-2-ulosonic acid 3-hydroxylases, which catalyse the conversion of 3-deoxy-D-manno-oct-2-ulosonic acid (Kdo) to D-glycero-D-talo-oct-2-ulosonic acid (Ko). It contains a potential iron-binding motif, HXDX(n)H (n>40). Hydroxylation activity is iron-dependent [1].

1: Dioxygenases in Burkholderia ambifaria and Yersinia pestis that hydroxylate the outer Kdo unit of lipopolysaccharide. Chung HS, Raetz CR; Proc Natl Acad Sci U S A. 2011;108:510-515. PMID:21178073