the biosynthesis of a hypermodified nucleotide , similar to or identical with 3- ( 3-amino-3-carboxypropyl ) -1-methylpseudouridine monophosphate , present in saccharomyces carlsbergensis 17s and hela-cell 18s rrna , was investigated with respect to the sequence of reactions required for synthesis and their timing in ribosome maturation .
C0035701
rrna
C0035553
ribosome