mature_miRNA miRNA* pre-miRNA EST_contig mismatches bulges arm species source_database RFAM_best_hit RFAM_lowest_evalue miRBase_best_hit miRBase_lowest_evalue folding_energy secondary_structure TTTGGCTTGGAAGCCAGACC TCTGGCTACCAAGCGAGACC TTGAGTTTGGCTTGGAAGCCAGACCCAACAGCTTTTAGAAACGATTTGGGTCTGGCTACCAAGCGAGACCCAA 2 0 5' arm Populus_trichocarpa pmrd MIR474 8e-35 100 -38.43 .((.((((.((((((.((((((((((((.................)))))))))))).)))))).)))).)). (-38.43)