PDSS1 is also known as DPS1 or TPRT. The protein encoded by this gene is an enzyme that elongates the prenyl side-chain of coenzyme Q (also known as ubiquinone), one of the key elements in the respiratory chain. It catalyses the formation of all-trans polyprenyl pyrophosphates from isopentyl diphosphate during the assembly of polyisoprenoid side chains - the first step in coenzyme Q biosynthesis. PDSS1 forms a functional heterodimer with the PDSS2 subunit, which is responsible for catalysing the chain elongation reaction of isopentenyl diphosphate to generate isoprenoid precursors of varying lengths, such as farnesyl diphosphate and geranylgeranyl diphosphate. These products are fundamental to the synthesis of essential molecules such as cholesterol, ubiquinone, heme A and protein isoprenylation modifications, as well as being vital for other biological processes. Therefore, PDSS1 directly influences key physiological processes in cells by regulating isoprenoid synthesis, including energy metabolism, membrane stability, signal transduction, and antioxidant defence.