Streptococcal arginine deiminase system (ADS)

The Streptococcal arginine deiminase system (ADS) is a multi-enzyme pathway—comprising arginine deiminase (ArcA), ornithine transcarbamylase (ArcB), and carbamate kinase (ArcC)—coupled with an arginine-ornithine antiporter (ArcD) (Burne & Marquis, 2000, Microbes and Infection). Its primary function is the catabolism of L-arginine to produce ornithine, CO2, and ammonia, generating one mole of ATP per mole of arginine (Liu et al., 2008, Journal of Bacteriology). The ammonia produced serves to neutralize environmental acidity, providing a significant survival advantage to streptococci in low-pH niches like the oral cavity or within host phagosomes (Quivey et al., 2001, Critical Reviews in Oral Biology & Medicine). In commensal oral streptococci, ADS activity is associated with a reduced risk of dental caries by counteracting the acid produced by cariogenic species (Nascimento et al., 2009, Oral Microbiology and Immunology). However, in pathogens such as Streptococcus pyogenes, the ADS acts as a virulence factor that supports intracellular persistence and modulates the host immune response (Cusumano et al., 2014, PLOS Pathogens). Because the ADS is absent in humans, it is considered a viable target for antimicrobial therapies, with research focusing on small-molecule inhibitors to disrupt bacterial pH homeostasis and energy production (Zhu et al., 2017, Scientific Reports).

Other names

Arginine deiminase pathwayADI pathwayArc systemArginine catabolic pathway

Competitive inhibition of arginine deiminase and disruption of bacterial pH homeostasis