separation of active and inactive molecules after irradiation has shown that ultraviolet light modification of the uridine in the anticodon , the uridine in the small loop , the 4-thiouridine , and the pyrimidines in the double-stranded stem adjacent to the dihydrouridine loop has no effect on aminoacylation or transformylation .
C0041984
uridine
C0034289
pyrimidines