ENZYMATIC N-RIBOSIDE SCISSION IN RNA AND RNA PRECURSORS

N-ribohydrolases and transferases act on nucleosides, nucleotides and oligonucleotides to effect base removal. Advances in mechanistic and s tructural analysis have established that enzymes of N-riboside scissio n act by combinations of leaving-group and ribosyl activation. Alterna tive O-riboside substrates have been developed for mechanistic diagnos is, Transition-state structures have been determined, and powerful inh ibitors have been designed from structural and transition-state inform ation.