Filamentous Structure of Cytidine Triphosphate Synthase

Nucleotide biosynthesis is a highly regulated process essential for cell growth and replication. Cytidine triphosphate synthase (CTPsyn) is a metabolic enzyme that catalyzes the rate-limiting step of de novo CTP biosynthesis. In addition to being an essential nucleotide, CTP is a basic building molecule (or block) of RNA, DNA, and phospholipids. Recently, CTPsyn was independently revealed to have a filamentous structure in bacteria, budding yeast, Drosophila, and mammalian cell lines, indicating that its structure is highly evolutionarily conserved. In the present review, we briefly discuss recent findings and suggest that future studies investigating the biological effect of the polymeric structure of CTPsyn will be expected.