3-deoxy-D-manno-oct-2-ulosonic acid (KDO) biosynthetic pathway enzymes (KDO pathway enzymes)

3-deoxy-D-manno-oct-2-ulosonic acid (KDO) biosynthetic pathway enzymes are a group of essential bacterial proteins responsible for the synthesis and activation of KDO, a unique eight-carbon sugar required for the assembly of lipopolysaccharides (LPS) in Gram-negative bacteria (Cipolla et al., 2010, PMID: 21114433). LPS is a fundamental component of the bacterial outer membrane, providing a robust physical barrier against antibiotics and host immune responses (UniProt, 2024). The pathway involves several key enzymes, including KDO-8-phosphate synthase (KdsA), KDO-8-phosphate phosphatase (KdsC), CMP-KDO synthetase (KdsB), and KDO transferase (WaaA), which collectively ensure the incorporation of KDO into the lipid A-core region (PubChem, 2024). Because KDO is essential for the viability of most Gram-negative pathogens and the pathway is entirely absent in humans, these enzymes are considered high-value targets for the development of novel, narrow-spectrum antibiotics (Cipolla et al., 2010). Inhibition of these enzymes leads to the production of truncated LPS or the complete failure of outer membrane assembly, resulting in bacterial cell death or extreme sensitization to other antimicrobial agents. While several potent inhibitors have been identified in research settings, such as KDO and CTP analogs, their clinical progression has been limited by challenges in penetrating the complex Gram-negative cell envelope (PMID: 19157056).

Other names

KDO-utilizing enzymesKDO biosynthetic pathway3-deoxy-D-manno-oct-2-ulosonic acid pathwayKDO metabolism enzymes2-keto-3-deoxy-octonate pathwayKdsA/KdsB/WaaA pathway

Inhibition of the biosynthesis or transfer of 3-deoxy-D-manno-oct-2-ulosonic acid (KDO), which prevents the assembly of functional lipopolysaccharides (LPS) and compromises the bacterial outer membrane.