Cryo-EM structure of DICER with pre-mir-517a-GU in dicing state. Determined by electron microscopy at 3.21 Å resolution. Released 11 Mar 2026.
Explore 21CN in 3D Show helices and sheets RCSB PDB PDBe
21CN contains 33 α-helices and 15 β-strands across 1 chain. Residue ranges use author residue numbering, as in the PDB file, from PDBe. To see them in 3D, choose the Cartoon representation with Secondary structure coloring: helices, sheets and coils get different colors.
| Element | Residues | Length | Sheet |
|---|---|---|---|
| α-helix | 749-751 | 3 | |
| α-helix | 755-757 | 3 | |
| β-strand | 771 | 1 | 1 |
| β-strand | 802-805 | 4 | 2 |
| β-strand | 806 | 1 | 1 |
| β-strand | 834 | 1 | 1 |
| α-helix | 840-852 | 13 | |
| α-helix | 853-857 | 5 | |
| β-strand | 862 | 1 | 3 |
| β-strand | 865 | 1 | 3 |
| β-strand | 877-880 | 4 | 2 |
| β-strand | 882 | 1 | 4 |
| β-strand | 891 | 1 | 4 |
| α-helix | 894-902 | 9 | |
| α-helix | 919-921 | 3 | |
| β-strand | 932 | 1 | 5 |
| β-strand | 945 | 1 | 5 |
| β-strand | 947-949 | 3 | 6 |
| α-helix | 952 | 1 | |
| α-helix | 968-971 | 4 | |
| α-helix | 972-976 | 5 | |
| β-strand | 988-989 | 2 | 6 |
| α-helix | 1013-1027 | 15 | |
| α-helix | 1054-1073 | 20 | |
| α-helix | 1294-1301 | 8 | |
| α-helix | 1313-1334 | 22 | |
| α-helix | 1343-1350 | 8 | |
| α-helix | 1351-1355 | 5 | |
| α-helix | 1356-1363 | 8 | |
| α-helix | 1376-1379 | 4 | |
| α-helix | 1381-1382 | 2 | |
| α-helix | 1556-1574 | 19 | |
| α-helix | 1576-1586 | 11 | |
| α-helix | 1661-1672 | 12 | |
| α-helix | 1684-1687 | 4 | |
| β-strand | 1688 | 1 | 7 |
| α-helix | 1699-1700 | 2 | |
| α-helix | 1702-1721 | 20 | |
| α-helix | 1724-1726 | 3 | |
| α-helix | 1729-1740 | 12 | |
| α-helix | 1742-1750 | 9 | |
| β-strand | 1759 | 1 | 7 |
| α-helix | 1763-1775 | 13 | |
| α-helix | 1803-1804 | 2 | |
| α-helix | 1806-1822 | 17 | |
| α-helix | 1827-1844 | 18 | |
| α-helix | 1852-1859 | 8 | |
| α-helix | 1897-1911 | 15 |
| Molecule | Chains | Type | Length | Organism | UniProt |
|---|---|---|---|---|---|
| Endoribonuclease Dicer | D | protein | 1909 | Homo sapiens | Q9UPY3 (AlphaFold model) |
| RNA (61-mer) | A | RNA | 61 | Homo sapiens |
>21CN_1 Endoribonuclease Dicer (chains D) MGHHHHHHHHHHPFFGLPWQQEAIHDNIYTPRKYQVELLEAALDHNTIVCLNTGSGKTFI AVLLTKELSYQIRGDFSRNGKRTVFLVNSANQVAQQVSAVRTHSDLKVGEYSNLEVNASW TKERWNQEFTKHQVLIMTCYVALNVLKNGYLSLSDINLLVFDECHLAILDHPYREIMKLC ENCPSCPRILGLTASILNGKCDPEELEEKIQKLEKILKSNAETATDLVVLDRYTSQPCEI VVDCGPFTDRSGLYERLLMELEEALNFINDCNISVHSKERDSTLISKQILSDCRAVLVVL GPWCADKVAGMMVRELQKYIKHEQEELHRKFLLFTDTFLRKIHALCEEHFSPASLDLKFV TPKVIKLLEILRKYKPYERQQFESVEWYNNRNQDNYVSWSDSEDDDEDEEIEEKEKPETN FPSPFTNILCGIIFVERRYTAVVLNRLIKEAGKQDPELAYISSNFITGHGIGKNQPRNKQ MEAEFRKQEEVLRKFRAHETNLLIATSIVEEGVDIPKCNLVVRFDLPTEYRSYVQSKGRA RAPISNYIMLADTDKIKSFEEDLKTYKAIEKILRNKCSKSVDTGETDIDPVMDDDDVFPP YVLRPDDGGPRVTINTAIGHINRYCARLPSDPFTHLAPKCRTRELPDGTFYSTLYLPINS PLRASIVGPPMSCVRLAERVVALICCEKLHKIGELDDHLMPVGKETVKYEEELDLHDEEE TSVPGRPGSTKRRQCYPKAIPECLRDSYPRPDQPCYLYVIGMVLTTPLPDELNFRRRKLY PPEDTTRCFGILTAKPIPQIPHFPVYTRSGEVTISIELKKSGFMLSLQMLELITRLHQYI FSHILRLEKPALEFKPTDADSAYCVLPLNVVNDSSTLDIDFKFMEDIEKSEARIGIPSTK YTKETPFVFKLEDYQDAVIIPRYRNFDQPHRFYVADVYTDLTPLSKFPSPEYETFAEYYK TKYNLDLTNLNQPLLDVDHTSSRLNLLTPRHLNQKGKALPLSSAEKRKAKWESLQNKQIL VPELCAIHPIPASLWRKAVCLPSILYRLHCLLTAEELRAQTASDAGVGVRSLPADFRYPN LDFGWKKSIDSKSFISISNSSSAENDNYCKHSTIVPENAAHQGANRTSSLENHDQMSVNC RTLLSESPGKLHVEVSADLTAINGLSYNQNLANGSYDLANRDFCQGNQLNYYKQEIPVQP TTSYSIQNLYSYENQPQPSDECTLLSNKYLDGNANKSTSDGSPVMAVMPGTTDTIQVLKG RMDSEQSPSIGYSSRTLGPNPGLILQALTLSNASDGFNLERLEMLGDSFLKHAITTYLFC TYPDAHEGRLSYMRSKKVSNCNLYRLGKKKGLPSRMVVSIFDPPVNWLPPGYVVNQDKSN TDKWEKDEMTKDCMLANGKLDEDYEEEDEEEESLMWRAPKEEADYEDDFLEYDQEHIRFI DNMLMGSGAFVKKISLSPFSTTDSAYEWKMPKKSSLGSMPFSSDFEDFDYSSWDAMCYLD PSKAVEEDDFVVGFWNPSEENCGVDTGKQSISYDLHTEQCIADKSIADCVEALLGCYLTS CGERAAQLFLCSLGLKVLPVIKRTDREKALCPTRENFNSQQKNLSVSCAAASVASSRSSV LKDSEYGCLKIPPRCMFDHPDADKTLNHLISGFENFEKKINYRFKNKAYLLQAFTHASYH YNTITDCYQRLEFLGDAILDYLITKHLYEDPRQHSPGVLTDLRSALVNNTIFASLAVKYD YHKYFKAVSPELFHVIDDFVQFQLEKNEMQGMDSELRRSEEDEEKEEDIEVPKAMGDIFE SLAGAIYMDSGMSLETVWQVYYPMMRPLIEKFSANVPRSPVRELLEMEPETAKFSPAERT YDGKVRVTVEVVGKGKFKGVGRSYRIAKSAAARRALRSLKANQPQVPNS
>21CN_2 RNA (61-MER) (chains A) GCUCUAGAUGGAAGCACUGUCUGUUGUAUAAAAGAAAAGAUCGUGCAUCCCUUUAGAGUG U
| ID | Name | Formula | Copies |
|---|---|---|---|
| CA | Calcium ion | Ca | 2 |
DICER cleavage fidelity is governed by 5'-end binding pockets. Ngo, M.K., Le, C.T., Nguyen, T.A. Nature (2026) 653:611-620. DOI 10.1038/s41586-026-10211-5 · PubMed
Other PDB entries of the same protein (UniProt Q9UPY3 (AlphaFold model), which also has an AlphaFold model), best resolution first:
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