<Tr> <Td> Phenylalanine </Td> <Td> MKHIPFFFAFFFTFP stop </Td> <Td> Lactis - leu - phe leader RNA motif </Td> </Tr> <P> Research conducted on microRNA processing showed an evidence of attenuation process in Eukaryotes . After co-transcriptional endonucleolitical cleavage by Drosha 5' -> 3' exonuclease XRN2 may terminate further transcription by torpedo mechanism . </P>

A key factor controlling attenuation in the trp operon is the number of trna molecules charged with