Project description:we resolved precusor let7 (pre-let-7) and human Dicer-TRBP complex bound precusor let7 (hDicer-TRBP-pre-let-7) secondary structure based on in vivo click selective 2'-hydroxyl acylation and profiling experiment (icSHAPE). We found the free pre-let-7 RNA is more flexible comparing with hDicer-TRBP-pre-7 in the double strand region [10-20nt and 50- 60 nt].