Cryo-EM structure of DICER with pre-mir-517a-GU in pre-dicing state. Determined by electron microscopy at 3.0 Å resolution. Released 11 Mar 2026.
Explore 21CB in 3D Show helices and sheets RCSB PDB PDBe
21CB contains 65 α-helices and 45 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 |
|---|---|---|---|
| β-strand | 45 | 1 | 1 |
| α-helix | 46-49 | 4 | |
| α-helix | 52-57 | 6 | |
| β-strand | 60 | 1 | 2 |
| α-helix | 70-80 | 11 | |
| α-helix | 82-85 | 4 | |
| α-helix | 89-91 | 3 | |
| β-strand | 96-100 | 5 | 3 |
| α-helix | 103-114 | 12 | |
| α-helix | 120 | 1 | |
| β-strand | 121 | 1 | 3 |
| α-helix | 135-144 | 10 | |
| β-strand | 147-151 | 5 | 3 |
| α-helix | 152-160 | 9 | |
| α-helix | 166-168 | 3 | |
| β-strand | 171-173 | 3 | 2 |
| α-helix | 177-181 | 5 | |
| α-helix | 185-195 | 11 | |
| β-strand | 201-203 | 3 | 2 |
| α-helix | 216-229 | 14 | |
| α-helix | 269-282 | 14 | |
| α-helix | 291-293 | 3 | |
| α-helix | 298-308 | 11 | |
| α-helix | 317-330 | 14 | |
| α-helix | 332-333 | 2 | |
| α-helix | 340-362 | 23 | |
| α-helix | 375-384 | 10 | |
| β-strand | 444-447 | 4 | 4 |
| α-helix | 452-465 | 14 | |
| α-helix | 469-472 | 4 | |
| β-strand | 478 | 1 | 4 |
| α-helix | 493-507 | 15 | |
| β-strand | 515-517 | 3 | 4 |
| β-strand | 534-536 | 3 | 4 |
| α-helix | 543-552 | 10 | |
| α-helix | 569-588 | 20 | |
| β-strand | 589 | 1 | 5 |
| β-strand | 595 | 1 | 5 |
| α-helix | 603-604 | 2 | |
| α-helix | 626-640 | 15 | |
| β-strand | 654-657 | 4 | 6 |
| β-strand | 663-667 | 5 | 6 |
| β-strand | 679-680 | 2 | 6 |
| α-helix | 681-683 | 3 | |
| β-strand | 684 | 1 | 6 |
| α-helix | 687-705 | 19 | |
| β-strand | 708 | 1 | 7 |
| α-helix | 710-712 | 3 | |
| β-strand | 714 | 1 | 7 |
| β-strand | 720 | 1 | 8 |
| β-strand | 723 | 1 | 8 |
| β-strand | 746-750 | 5 | 9 |
| α-helix | 751-752 | 2 | |
| β-strand | 769-773 | 5 | 10 |
| β-strand | 776-779 | 4 | 11 |
| α-helix | 780-782 | 3 | |
| α-helix | 783-785 | 3 | |
| α-helix | 795-797 | 3 | |
| β-strand | 801-806 | 6 | 10 |
| β-strand | 816-820 | 5 | 11 |
| β-strand | 823-827 | 5 | 11 |
| β-strand | 829-831 | 3 | 10 |
| α-helix | 840-852 | 13 | |
| α-helix | 853-857 | 5 | |
| β-strand | 865-867 | 3 | 12 |
| β-strand | 877-881 | 5 | 10 |
| β-strand | 882 | 1 | 13 |
| β-strand | 892 | 1 | 13 |
| α-helix | 895-902 | 8 | |
| α-helix | 924-927 | 4 | |
| β-strand | 931-934 | 4 | 14 |
| β-strand | 945 | 1 | 14 |
| β-strand | 949-951 | 3 | 15 |
| α-helix | 959-960 | 2 | |
| α-helix | 968-976 | 9 | |
| α-helix | 985-986 | 2 | |
| β-strand | 987-991 | 5 | 15 |
| β-strand | 992 | 1 | 14 |
| β-strand | 1030-1033 | 4 | 15 |
| α-helix | 1035-1037 | 3 | |
| β-strand | 1038-1041 | 4 | 14 |
| α-helix | 1045-1075 | 31 | |
| α-helix | 1294-1301 | 8 | |
| α-helix | 1304-1306 | 3 | |
| α-helix | 1313-1334 | 22 | |
| α-helix | 1340-1350 | 11 | |
| α-helix | 1353-1361 | 9 | |
| α-helix | 1365-1368 | 4 | |
| α-helix | 1373-1374 | 2 | |
| α-helix | 1376-1379 | 4 | |
| α-helix | 1381-1382 | 2 | |
| β-strand | 1385-1387 | 3 | 12 |
| β-strand | 1551-1555 | 5 | 9 |
| α-helix | 1558-1586 | 29 | |
| α-helix | 1656-1673 | 18 | |
| α-helix | 1680-1686 | 7 | |
| β-strand | 1688 | 1 | 16 |
| α-helix | 1702-1722 | 21 | |
| α-helix | 1731-1739 | 9 | |
| α-helix | 1742-1751 | 10 | |
| α-helix | 1755-1757 | 3 | |
| β-strand | 1759 | 1 | 16 |
| α-helix | 1763-1778 | 16 | |
| α-helix | 1806-1822 | 17 | |
| α-helix | 1828-1847 | 20 | |
| α-helix | 1849-1850 | 2 | |
| α-helix | 1853-1860 | 8 | |
| β-strand | 1865 | 1 | 17 |
| β-strand | 1884 | 1 | 17 |
| α-helix | 1897-1911 | 15 |
| Molecule | Chains | Type | Length | Organism | UniProt |
|---|---|---|---|---|---|
| Endoribonuclease Dicer | A | protein | 1909 | Homo sapiens | Q9UPY3 (AlphaFold model) |
| RNA (58-mer) | B | RNA | 61 | Homo sapiens |
>21CB_1 Endoribonuclease Dicer (chains A) 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
>21CB_2 RNA (58-MER) (chains B) GCUCUAGAUGGAAGCACUGUCUGUUGUAUAAAAGAAAAGAUCGUGCAUCCCUUUAGAGUG U
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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