Coenzyme A biosynthesis pathway enzymes (CoA biosynthesis enzymes)

Coenzyme A (CoA) is a vital cofactor required for numerous metabolic processes, including the tricarboxylic acid (TCA) cycle, fatty acid metabolism, and the regulation of gene expression through protein acetylation (Leonardi et al., 2005, PMID: 15695337). The biosynthesis of CoA from pantothenate (vitamin B5) is a highly conserved five-step pathway involving the enzymes pantothenate kinase (PANK), phosphopantothenoylcysteine synthetase (PPCS), phosphopantothenoylcysteine decarboxylase (PPCDC), phosphopantetheine adenylyltransferase (PPAT), and dephospho-CoA kinase (DPCK) (Robishaw & Neely, 1985, PMID: 3882355). In humans, the final two steps are catalyzed by the bifunctional enzyme Coenzyme A synthase (COASY) (Daugherty et al., 2002, PMID: 11923312). PANK serves as the primary rate-limiting enzyme and is subject to feedback inhibition by CoA and its thioesters, making it a focal point for therapeutic regulation (Zhang et al., 2006, PMID: 16434446). Dysregulation of this pathway is linked to severe pathologies, most notably Pantothenate Kinase-Associated Neurodegeneration (PKAN), caused by mutations in the PANK2 gene which lead to iron accumulation in the basal ganglia (Hayflick et al., 2003, PMID: 12668599). Additionally, because CoA biosynthesis is essential for the survival of pathogens like Plasmodium falciparum and Mycobacterium tuberculosis, these enzymes are actively pursued as targets for novel antimicrobial and antimalarial drugs (Spry et al., 2008, PMID: 18394149).

Other names

Pantothenate kinase pathwayCoA synthesis pathwayVitamin B5 metabolic pathwayCoenzyme A synthase complex

Allosteric activation of PANK to bypass genetic deficiency or competitive inhibition of bacterial CoA enzymes to arrest growth.