Bacterial folic acid biosynthesis pathway

Bacterial folic acid biosynthesis pathway refers to the set of enzymatic steps by which bacteria synthesize folate (vitamin B9) de novo from basic metabolic precursors, a process absent in higher animals that obtain folate from their diet. This pathway is essential for bacterial growth because folate serves as a cofactor in one-carbon transfer reactions central to DNA synthesis, repair, and amino acid production. The pathway involves several key enzymes, including guanine cyclohydrolase (GCYH I), dihydroneopterin hydrolase (DHNTPase), dihydroneopterin aldolase (DHNA), hydroxymethyl-dihydropteridine pyrophosphokinase (HPPK), dihydropteroate synthase (DHPS), dihydrofolate synthase (DHFS), and dihydrofolate reductase (DHFR)[1][3][5][6][7][8]. Many clinically relevant antibiotics, such as sulfonamides and trimethoprim, act by inhibiting distinct steps in this pathway, leading to bacterial cell death or stasis[1][5][7][8]. Because humans lack this biosynthetic pathway, it is an attractive and validated antimicrobial target, but resistance mechanisms—arising from target mutations or alternative metabolic routes—pose ongoing therapeutic challenges[1][5][6][7].

Other names

Bacterial folate biosynthesis pathwayBacterial folic acid metabolism pathwayBacterial dihydrofolate pathway

Inhibition of dihydropteroate synthase (e.g., by sulfonamides); Inhibition of dihydrofolate reductase (e.g., by trimethoprim)