InterPro domain: IPR004528

3-Deoxy-D-manno-octulosonate cytidylyltransferase ( 2.7.7.38 ) activates KDO, a required 8-carbon sugar, for incorporation into bacterial lipopolysaccharide in Gram-negative bacteria. It acts as a homodimer and catalyses the conversion of CTP and 3-deoxy-D-manno-octulosonate into CMP-3-deoxy-D-manno-octulosonate and pyrophosphate [ 1 , 2 ]. KDO is an essential component of the lipopolysaccharide found in the outer surface of Gram-negative eubacteria. It is also a constituent of the capsular polysaccharides of some Gram-negative eubacteria. Its presence in the cell wall polysaccharides of green algae and plant were also discovered. However, they have not been found in yeast and animals. The absence of the enzyme in mammalian cells makes it an attractive target molecule for drug design [ 3 ].

This family also includes 8-amino-3,8-dideoxy-manno-octulosonate cytidylyltransferase ( 2.7.7.90 ). This enzyme activates KDO8N, the 8-aminated form of KDO, for incorporation into bacterial lipopolysaccharide in the Shewanella genus. KDO8N is found exclusively in marine bacteria of the genus Shewanella [ 4 ].

1. Crystallization and preliminary X-ray crystallographic studies of 3-deoxy-manno-octulosonate cytidylyltransferase from Haemophilus influenzae. Acta Crystallogr. D Biol. Crystallogr. 59, 180-2
2. The three-dimensional structure of capsule-specific CMP: 2-keto-3-deoxy-manno-octonic acid synthetase from Escherichia coli. FEBS Lett. 391, 157-61
3. Design and synthesis of peptide derivatives of a 3-deoxy-D-manno-2-octulosonic acid (KDO) analogue as novel antibacterial agents acting upon lipopolysaccharide biosynthesis. J. Med. Chem. 30, 2309-13
4. The origin of 8-amino-3,8-dideoxy-D-manno-octulosonic acid (Kdo8N) in the lipopolysaccharide of Shewanella oneidensis. J. Biol. Chem. 288, 9216-25