dTDP-4-dehydrorhamnose reductase (RmlD)

dTDP-4-dehydrorhamnose reductase, commonly referred to as RmlD, is an essential enzyme in the rhamnose biosynthesis pathway of numerous pathogenic bacteria and protozoans (Wellcome Open Research, 2025; NIH, 2020). It catalyzes the final, NADPH-dependent reduction of dTDP-6-deoxy-L-lyxo-4-hexulose to dTDP-L-rhamnose, a vital precursor for the synthesis of L-rhamnose (Wellcome Open Research, 2025; ASM, 2001). This sugar is a key structural component of the cell wall and surface lipoglycans in pathogens such as Mycobacterium tuberculosis, Streptococcus pyogenes, and Trichomonas vaginalis (Wellcome Open Research, 2025; NIH, 2020). Since the rhamnose biosynthetic pathway is absent in humans, RmlD represents a highly selective therapeutic target with a low risk of off-target toxicity (Wellcome Open Research, 2025; ASM, 2001). Inhibition of this enzyme disrupts cell wall integrity, leading to reduced bacterial viability, impaired biofilm formation, and attenuated virulence (ASM, 2001; Wellcome Open Research, 2025). Although no RmlD inhibitors have reached clinical approval, several experimental compounds, including Ri03 and various small molecules identified through virtual screening, have demonstrated potent inhibitory activity in preclinical models (BioRxiv, 2018; ASM, 2001). The development of RmlD-targeted therapies offers a promising strategy for combating multidrug-resistant infections by exploiting a unique metabolic vulnerability in pathogens (Wellcome Open Research, 2025; NIH, 2020).

Other names

dTDP-6-deoxy-L-lyxo-4-hexulose reductaseGacARfbDdTDP-4-keto-6-deoxy-D-glucose 4-reductasedTDP-L-rhamnose synthase

Enzyme inhibition leading to the disruption of dTDP-L-rhamnose biosynthesis and subsequent impairment of cell wall integrity and virulence.