Deciphering the Complex Enzymatic Pathway for Biosynthesis of Wyosine Derivatives in Anticodon of tRNA Phe
Jaunius Jaunius Urbonavičius, Louis Droogmans, Jean Armengaud and Henri Grosjean
Wyosine derivatives are tricyclic ribonucleosides present exclusively at position 37 of tRNA specific for phenylalanine in most Eukarya (cytoplasmic only) and Archaea, but not Bacteria. They occur by posttranscriptional modification of encoded guanosine in the tRNA precursor. Depending on the organism examined, eight wyosine derivatives have been identified in naturally occurring tRNAPhe, eleven if one also includes biosynthetic intermediates. The large diversity of wyosine derivatives attests to the existence of complex biosynthetic routes that differ from one organism to another. In this review, we describe the chemical structures of these hypermodified guanosine derivatives and the biosynthetic pathway of the wyosine derivative found in Saccharomyces cerevisiae. Not surprisingly given their location at position 37, 3′ adjacent to the GAA anticodon, wyosine derivatives have been demonstrated to play an essential role in translation, particularly in the regulation of frameshifting.