The molecule is a polynucleotide comprised of uridine units connected via 3'->5' phosphodiester linkages. It contains an UMP 3'-end residue, an UMP 5'-end residue and a uridine 5'-monophosphate residue.
[(2R,3S,4R,5R)-5-(2,4-dioxopyrimidin-1-yl)-3,4-dihydroxyoxolan-2-yl]methyl [(2R,3S,4R,5R)-5-(2,4-dioxopyrimidin-1-yl)-2-[[[(2R,3S,4R,5R)-5-(2,4-dioxopyrimidin-1-yl)-4-hydroxy-2-(hydroxymethyl)oxolan-3-yl]oxy-hydroxyphosphoryl]oxymethyl]-4-hydroxyoxolan-3-yl] hydrogen phosphate