Pseudouridine: Still mysterious, but never a fake (uridine)!

International audiencePseudouridine () is the most abundant of >150 nucleoside modifications in RNA. Although was discovered as the first modified nucleoside more than half a century ago, neither the enzymatic mechanism of its formation, nor the function of this modification are fully elucidated. We present the consistent picture of synthases, their substrates and their substrate positions in model organisms of all domains of life as it has emerged to date and point out the challenges that remain concerning higher eukaryotes and the elucidation of the enzymatic mechanism