FnoCas12a bridge helix variant state 4a. Determined by electron microscopy at 3.63 Å resolution. Released 11 Feb 2026.
Explore 9MKW in 3D Show helices and sheets RCSB PDB PDBe
9MKW contains 63 α-helices and 35 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 | 4-6 | 3 | |
| β-strand | 13-22 | 10 | 1 |
| α-helix | 27-34 | 8 | |
| α-helix | 36-66 | 31 | |
| α-helix | 73-86 | 14 | |
| α-helix | 92-115 | 24 | |
| α-helix | 117-120 | 4 | |
| α-helix | 125-127 | 3 | |
| α-helix | 138-147 | 10 | |
| α-helix | 153-156 | 4 | |
| α-helix | 162-170 | 9 | |
| α-helix | 176-190 | 15 | |
| α-helix | 199-202 | 4 | |
| α-helix | 203-207 | 5 | |
| α-helix | 208-224 | 17 | |
| α-helix | 232-237 | 6 | |
| β-strand | 244 | 1 | 2 |
| β-strand | 256 | 1 | 2 |
| α-helix | 261-263 | 3 | |
| α-helix | 267-271 | 5 | |
| α-helix | 275-286 | 12 | |
| α-helix | 300-311 | 12 | |
| α-helix | 314-318 | 5 | |
| α-helix | 345-361 | 17 | |
| α-helix | 370-382 | 13 | |
| β-strand | 392-394 | 3 | 3 |
| α-helix | 398-402 | 5 | |
| α-helix | 403-407 | 5 | |
| α-helix | 413-422 | 10 | |
| β-strand | 450-452 | 3 | 3 |
| α-helix | 453-466 | 14 | |
| α-helix | 475-505 | 31 | |
| α-helix | 520-539 | 20 | |
| α-helix | 559-572 | 14 | |
| α-helix | 575-585 | 11 | |
| β-strand | 596-597 | 2 | 1 |
| α-helix | 614-617 | 4 | |
| β-strand | 620-624 | 5 | 1 |
| β-strand | 627-633 | 7 | 1 |
| α-helix | 643-648 | 6 | |
| β-strand | 654-659 | 6 | 1 |
| α-helix | 669-673 | 5 | |
| α-helix | 679-682 | 4 | |
| α-helix | 686-694 | 9 | |
| α-helix | 701-704 | 4 | |
| α-helix | 715-730 | 16 | |
| α-helix | 734-737 | 4 | |
| α-helix | 750-759 | 10 | |
| β-strand | 764-769 | 6 | 1 |
| α-helix | 772-779 | 8 | |
| β-strand | 783-789 | 7 | 1 |
| α-helix | 791-793 | 3 | |
| α-helix | 803-811 | 9 | |
| α-helix | 814-818 | 5 | |
| β-strand | 823-824 | 2 | 1 |
| β-strand | 829-833 | 5 | 1 |
| β-strand | 843 | 1 | 4 |
| β-strand | 848-850 | 3 | 5 |
| β-strand | 860-862 | 3 | 5 |
| β-strand | 867 | 1 | 4 |
| α-helix | 871-874 | 4 | |
| β-strand | 877-886 | 10 | 1 |
| α-helix | 898-906 | 9 | |
| β-strand | 912-916 | 5 | 6 |
| β-strand | 925-929 | 5 | 6 |
| β-strand | 935-940 | 6 | 6 |
| β-strand | 943 | 1 | 7 |
| β-strand | 952 | 1 | 7 |
| α-helix | 954-960 | 7 | |
| α-helix | 978-996 | 19 | |
| β-strand | 1001-1002 | 2 | 6 |
| β-strand | 1004-1005 | 2 | 8 |
| α-helix | 1023-1035 | 13 | |
| β-strand | 1038 | 1 | 9 |
| α-helix | 1044 | 1 | |
| β-strand | 1055 | 1 | 9 |
| α-helix | 1059-1061 | 3 | |
| α-helix | 1064-1066 | 3 | |
| β-strand | 1070-1071 | 2 | 8 |
| β-strand | 1074-1076 | 3 | 8 |
| α-helix | 1095-1097 | 3 | |
| α-helix | 1102-1108 | 7 | |
| β-strand | 1116-1118 | 3 | 10 |
| β-strand | 1123-1125 | 3 | 10 |
| β-strand | 1127-1128 | 2 | 11 |
| α-helix | 1130-1132 | 3 | |
| α-helix | 1141 | 1 | |
| β-strand | 1142-1143 | 2 | 11 |
| α-helix | 1144 | 1 | |
| α-helix | 1173-1179 | 7 | |
| α-helix | 1185-1187 | 3 | |
| α-helix | 1191-1197 | 7 | |
| α-helix | 1201-1214 | 14 | |
| β-strand | 1218 | 1 | 12 |
| β-strand | 1229 | 1 | 12 |
| α-helix | 1254-1266 | 13 | |
| α-helix | 1271-1274 | 4 | |
| α-helix | 1288-1298 | 11 |
| Molecule | Chains | Type | Length | Organism | UniProt |
|---|---|---|---|---|---|
| CRISPR-associated endonuclease Cas12a | A | protein | 1305 | Francisella tularensis subsp. novicida | A0Q7Q2 (AlphaFold model) |
| RNA (36-mer) | B | RNA | 43 | synthetic construct | |
| Ts DNA | C | DNA | 24 | synthetic construct | |
| Nts DNA | D | DNA | 24 | synthetic construct |
>9MKW_1 CRISPR-associated endonuclease Cas12a (chains A) GAASHMSIYQEFVNKYSLSKTLRFELIPQGKTLENIKARGLILDDEKRAKDYKKAKQIID KYHQFFIEEILSSVCISEDLLQNYSDVYFKLKKSDDDNLQKDFKSAKDTIKKQISEYIKD SEKFKNLFNQNLIDAKKGQESDLILWLKQSKDNGIELFKANSDITDIDEALEIIKSFKGW TTYFKGFHENRKNVYSSNDIPTSIIYRIVDDNLPKFLENKAKYESLKDKAPEAINYEQIK KDLAEELTFDIDYKTSEVNQRVFSLDEVFEIANFNNYLNQSGITKFNTIIGGKFVNGENT KRKGINEYINLYSQQINDKTLKKYKMSVLFKQILSDTESKSFVIDKLEDDSDVVTTMQSF YEQIAAFKTVEEKSIKETLSLLFDDLKAQKLDLSKIYFKNDKSLTDLSQQVFDDYSVIGT AVLEYITQQIAPKNLDNPSKKEQELIAKKTEKAKYLSLETIKLALEEFNKHRDIDKQCRF EEILANFAAIPMIFDEIAQNKDNLAQISIKYQNQGKKDLLQASAEDDVKAIKDLLDQTNN LLHKLKIFHISQSEDKANILDKDEHFYLVFEECYFELANIVPLYNKIRNYITQKPYSDEK FKLNFENSTLANGWDKNKEPDNTAILFIKDDKYYLGVMNKKNNKIFDDKAIKENKGEGYK KIVYKLLPGANKMLPKVFFSAKSIKFYNPSEDILRIRNHSTHTKNGSPQKGYEKFEFNIE DCRKFIDFYKQSISKHPEWKDFGFRFSDTQRYNSIDEFYREVENQGYKLTFENISESYID SVVNQGKLYLFQIYNKDFSAYSKGRPNLHTLYWKALFDERNLQDVVYKLNGEAELFYRKQ SIPKKITHPAKEAIANKNKDNPKKESVFEYDLIKDKRFTEDKFFFHCPITINFKSSGANK FNDEINLLLKEKANDVHILSIDRGERHLAYYTLVDGKGNIIKQDTFNIIGNDRMKTNYHD KLAAIEKDRDSARPPWKKINNIKEMKEGYLSQVVHEIAKLVIEYNAIVVFEDLNFGFKRG RFKVEKQVYQKLEKMLIEKLNYLVFKDNEFDKTGGVLRAYQLTAPFETFKKMGKQTGIIY YVPAGFTSKICPVTGFVNQLYPKYESVSKSQEFFSKFDKICYNLDKGYFEFSFDYKNFGD KAAKGKWTIASFGSRLINFRNSDKNHNWDTREVYPTKELEKLLKDYSIEYGHGECIKAAI CGESDKKFFAKLTSVLNTILQMRNSKTGTELDYLISPVADVNGNFFDSRQAPKNMPQDAD ANGAYHIGLKGLMLLGRIKNNQEGKKLNLVIKNEEYFEFVQNRNN
>9MKW_2 RNA (36-MER) (chains B) AAUUUCUACUGUUGUAGAUGAGAAGUCAUUUAAUAAGGCCACU
>9MKW_3 TS DNA (chains C) GCCTTATTAAATGACTTCTCTAAA
>9MKW_4 NTS DNA (chains D) TTTAGAGAAGTCATTTAATAAGGC
Bridge helix of Cas12a is an allosteric regulator of R-loop formation and RuvC activation. Ganguly, C., Aribam, S.D., Dos Santos, A.M. et al. Nat Commun (2026) 17. DOI 10.1038/s41467-026-68657-0 · PubMed
Other PDB entries of the same protein (UniProt A0Q7Q2 (AlphaFold model), which also has an AlphaFold model), best resolution first:
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