TRNA pseudouridine38/39 synthase

tRNA pseudouridine^38/39 synthase (EC 5.4.99.45, Deg1, Pus3p, pseudouridine synthase 3) is an enzyme with systematic name tRNA-uridine^38/39 uracil mutase.^[1][2] This enzyme catalyses the following chemical reaction

tRNA uridine^38/39 ${\displaystyle \rightleftharpoons }$ tRNA pseudouridine^38/39

The enzyme from Saccharomyces cerevisiae is active only towards uridine³⁸ and uridine³⁹.