The enzyme from Chlamydia psittaci transfers four Kdo residues to lipid A, forming a branched tetrasaccharide with the structure alpha-Kdo-(2,8)-[alpha-Kdo-(2,4)]-alpha-Kdo-(2,4)-alpha-Kdo (cf. EC
2.4.99.12 [lipid IVA 3-deoxy-D-manno-octulosonic acid transferase], EC
2.4.99.13 [(Kdo)-lipid IVA 3-deoxy-D-manno-octulosonic acid transferase], and EC
2.4.99.14 [(Kdo)2-lipid IVA (2-8) 3-deoxy-D-manno-octulosonic acid transferase]).