[English] 日本語
Yorodumi
- EMDB-54943: Type I-F_HNH variant Cascade bound to dsDNA, HNH domain in middle... -

+
Open data


ID or keywords:

Loading...

-
Basic information

Entry
Database: EMDB / ID: EMD-54943
TitleType I-F_HNH variant Cascade bound to dsDNA, HNH domain in middle position
Map data
Sample
  • Complex: Type I-F_HNH effector complex bound to dsDNA
    • Protein or peptide: Cas6f
    • Protein or peptide: Cas8f
  • Protein or peptide: Cas5f
  • Protein or peptide: Cas7f
  • DNA: Non-target strand
  • DNA: Target strand
  • RNA: crRNA
KeywordsCRISPR-Cas Type I-F HNH nuclease / RNA BINDING PROTEIN
Function / homology
Function and homology information


maintenance of CRISPR repeat elements / endonuclease activity / nucleic acid binding / zinc ion binding
Similarity search - Function
CRISPR-associated protein Csy1 / CRISPR-associated protein (Cas_Csy1) / HNH endonuclease / HNH endonuclease / CRISPR-associated endoribonuclease Cas6/Csy4, subtype I-F/YPEST / CRISPR-associated endoribonuclease Cas6/Csy4, subtype I-F/YPEST superfamily / CRISPR-associated protein (Cas_Csy4) / CRISPR-associated protein Csy2 / CRISPR-associated protein (Cas_Csy2) / HNH nucleases ...CRISPR-associated protein Csy1 / CRISPR-associated protein (Cas_Csy1) / HNH endonuclease / HNH endonuclease / CRISPR-associated endoribonuclease Cas6/Csy4, subtype I-F/YPEST / CRISPR-associated endoribonuclease Cas6/Csy4, subtype I-F/YPEST superfamily / CRISPR-associated protein (Cas_Csy4) / CRISPR-associated protein Csy2 / CRISPR-associated protein (Cas_Csy2) / HNH nucleases / CRISPR-associated protein Csy3 / CRISPR-associated protein (Cas_Csy3) / HNH nuclease
Similarity search - Domain/homology
Cas5f / Cas6f / Cas7f / Cas8f fusion with HNH
Similarity search - Component
Biological speciesSelenomonas sp. (bacteria)
Methodsingle particle reconstruction / cryo EM / Resolution: 1.92 Å
AuthorsFuglsang A / Montoya G
Funding support Denmark, 1 items
OrganizationGrant numberCountry
Novo Nordisk FoundationNNF14CC0001 Denmark
CitationJournal: Nucleic Acids Res / Year: 2026
Title: Conformational dynamics of CRISPR-Cas type I-F-HNH inform nickase engineering in a cascade scaffold.
Authors: Anders Fuglsang / Sweta Suman Rout / Eliska Bartl Koutna / Nicholas Sofos / Alejandro Redondo Gallego / Guillermo Montoya /
Abstract: The type I-FHNH CRISPR-Cas system is a non-canonical Class 1 effector complex distinguished by the replacement of the Cas3 recruitment domain with a catalytic HNH domain in Cas8, enabling autonomous ...The type I-FHNH CRISPR-Cas system is a non-canonical Class 1 effector complex distinguished by the replacement of the Cas3 recruitment domain with a catalytic HNH domain in Cas8, enabling autonomous DNA cleavage without accessory nucleases. Using cryo-EM, we determined high-resolution structures of the effector complex in three catalytic states-precatalytic, NTS-cleaved, and post-catalytic-revealing a dynamic trajectory of the HNH domain through inward, middle, and outward conformations. Biochemical assays demonstrated that the complex cleaves the nontarget strand (NTS) prior to the target strand (TS), consistent with a sequential cleavage mechanism similar to Cas12 effectors but notably lacking trans-cleavage activity on single-stranded DNA. Structural comparisons confirmed a minimal PAM requirement (5'-CN) and a constrained HNH catalytic site poised for precise strand scission. We engineered a ΔLinker variant of Cas8 that repositions the HNH domain, selectively abolishing TS cleavage and converting the system into a programmable NTS-specific nickase. Importantly, we validated the functionality of both wild-type and mutant complexes in human cells. While the wild-type system induced indels and base substitutions, the ΔLinker variant triggered targeted single-strand nicks without double-stranded breaks. Together, our work establishes type I-FHNH as a compact and precise genome editing platform with in vivo efficacy.
History
DepositionAug 31, 2025-
Header (metadata) releaseFeb 18, 2026-
Map releaseFeb 18, 2026-
UpdateFeb 18, 2026-
Current statusFeb 18, 2026Processing site: PDBe / Status: Released

-
Structure visualization

Supplemental images

emd_54943.png

Downloads & links

-
Map

FileDownload / File: emd_54943.map.gz / Format: CCP4 / Size: 282.6 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES)
Projections & slices

Image control

Size
Brightness
Contrast
Others
AxesZ (Sec.)Y (Row.)X (Col.)
0.73 Å/pix.
x 420 pix.
= 304.5 Å		0.73 Å/pix.
x 420 pix.
= 304.5 Å		0.73 Å/pix.
x 420 pix.
= 304.5 Å

Surface

Projections

Slices (1/3)

Slices (1/2)

Slices (2/3)

Images are generated by Spider.

Voxel sizeX=Y=Z: 0.725 Å
Density

Histogram

Histogram (log scale)
Contour LevelBy AUTHOR: 0.05
Minimum - Maximum-0.012370926 - 1.981277
Average (Standard dev.)0.001898319 (±0.030129846)
SymmetrySpace group: 1
Details

EMDB XML:

Map geometry
Axis orderXYZ
Origin000
Dimensions420420420
Spacing420420420
CellA=B=C: 304.5 Å
α=β=γ: 90.0 °

-
Supplemental data

-
Half map: #2

Fileemd_54943_half_map_1.map
Projections & Slices
AxesZYX

Projections

Slices (1/2)
Density Histograms

Histogram

Histogram (log scale)

-
Half map: #1

Fileemd_54943_half_map_2.map
Projections & Slices
AxesZYX

Projections

Slices (1/2)
Density Histograms

Histogram

Histogram (log scale)

-
Sample components

-
Entire : Type I-F_HNH effector complex bound to dsDNA

EntireName: Type I-F_HNH effector complex bound to dsDNA
Components
  • Complex: Type I-F_HNH effector complex bound to dsDNA
    • Protein or peptide: Cas6f
    • Protein or peptide: Cas8f
  • Protein or peptide: Cas5f
  • Protein or peptide: Cas7f
  • DNA: Non-target strand
  • DNA: Target strand
  • RNA: crRNA

-
Supramolecule #1: Type I-F_HNH effector complex bound to dsDNA

SupramoleculeName: Type I-F_HNH effector complex bound to dsDNA / type: complex / ID: 1 / Parent: 0 / Macromolecule list: #3, #1
Source (natural)Organism: Selenomonas sp. (bacteria)
Molecular weightTheoretical: 350 KDa

-
Macromolecule #1: Cas8f

MacromoleculeName: Cas8f / type: protein_or_peptide / ID: 1 / Number of copies: 1 / Enantiomer: LEVO
Source (natural)Organism: Selenomonas sp. (bacteria)
Molecular weightTheoretical: 39.339742 KDa
Recombinant expressionOrganism: Escherichia coli BL21(DE3) (bacteria)
SequenceString: MLRNKILAAI SQKIPEEQKI NKYIEGLFQS IDKNHLATHV AKFTETNSPG NIGAYDILSS DMNCGYLDTA NAGWKEPDIV TNDAKYKRP QGFVAMEMSD GRTVMEHLQE DSAELRHEME ELTDKYDEIR DGILNMPSMQ PYRTNQFIKQ VFFPVGGSYH L LSILPSTV ...String:
MLRNKILAAI SQKIPEEQKI NKYIEGLFQS IDKNHLATHV AKFTETNSPG NIGAYDILSS DMNCGYLDTA NAGWKEPDIV TNDAKYKRP QGFVAMEMSD GRTVMEHLQE DSAELRHEME ELTDKYDEIR DGILNMPSMQ PYRTNQFIKQ VFFPVGGSYH L LSILPSTV LNYEVSDRLY RSKIPKIRLR LLSSNAASTT GSRLVSKNKW PLVFQALPPK FLEKNLAKAL DKEYLLPDIN ID ELEGVDN GCLIDEALLP LIIDEGKRKG EGNYRPRHLR DERKEETVQA FLDKYGYCNI PVGYEVHHIV PLSQGGADSI KNM IMLSIE HHERVTEAHA SYFKWRNT

UniProtKB: Cas8f fusion with HNH

-
Macromolecule #2: Cas5f

MacromoleculeName: Cas5f / type: protein_or_peptide / ID: 2 / Number of copies: 1 / Enantiomer: LEVO
Source (natural)Organism: Selenomonas sp. (bacteria)
Molecular weightTheoretical: 28.703135 KDa
Recombinant expressionOrganism: Escherichia coli BL21(DE3) (bacteria)
SequenceString: MMKGYILLEK VNIENANAFN NIIVGIPAIT SFLGFARALE RKLNAKEIAI RINGVGLEFH EYELKGYKNK RGQYVTSCPL PGSIPGQNE KKLDAHIMNQ AYIDLNMSFL LEVEGPHVDM STCKSIKSTM ETLRIAGGII RNYKKIRLID TLADIPYGYF L TLRQDNLN ...String:
MMKGYILLEK VNIENANAFN NIIVGIPAIT SFLGFARALE RKLNAKEIAI RINGVGLEFH EYELKGYKNK RGQYVTSCPL PGSIPGQNE KKLDAHIMNQ AYIDLNMSFL LEVEGPHVDM STCKSIKSTM ETLRIAGGII RNYKKIRLID TLADIPYGYF L TLRQDNLN DAAGDDMLDK MIHALQQEDT LVPIAVGFKA LSEVGHVEGQ RDPEKDHCFV ESIFSLGGFE CSKILEDINS CL WRYKTEE GLYLCTII

UniProtKB: Cas5f

-
Macromolecule #3: Cas6f

MacromoleculeName: Cas6f / type: protein_or_peptide / ID: 3 / Number of copies: 1 / Enantiomer: LEVO
Source (natural)Organism: Selenomonas sp. (bacteria)
Molecular weightTheoretical: 20.735873 KDa
Recombinant expressionOrganism: Escherichia coli BL21(DE3) (bacteria)
SequenceString:
MFSQILIIKP GTGISPNIII SEDIFPVLHS LFVEHDKKFG ITFPAYSFDK KGHLGNIIEV LSEDKEALAS LCLEEHLAEV TDYVKVKKE ITFTDDYVLF KRIREENQYE TTARRMRKRG HTELGRPLEM HIKKKNQQIF CHAYIKVKSA STGQSYNIFL A PTDIKHGS FSAYGLLRGD THA

UniProtKB: Cas6f

-
Macromolecule #5: Cas7f

MacromoleculeName: Cas7f / type: protein_or_peptide / ID: 5 / Number of copies: 6 / Enantiomer: LEVO
Source (natural)Organism: Selenomonas sp. (bacteria)
Molecular weightTheoretical: 38.700172 KDa
Recombinant expressionOrganism: Escherichia coli BL21(DE3) (bacteria)
SequenceString: MAANKKATNV TLKSRPENLS FARCLNTTEA KFWQTDFLKR HTFKLPLLIT DKAVLASKGH EMPPDKLEKE IMDPNPQKSQ SCTLSTECD TLRIDFGIKV LPVKESMYSC SDYNYRTAIY QKIDEYIAED GFLTLAKRYV NNIANARFLW RNRKGAEIIE T IVTIEDKE ...String:
MAANKKATNV TLKSRPENLS FARCLNTTEA KFWQTDFLKR HTFKLPLLIT DKAVLASKGH EMPPDKLEKE IMDPNPQKSQ SCTLSTECD TLRIDFGIKV LPVKESMYSC SDYNYRTAIY QKIDEYIAED GFLTLAKRYV NNIANARFLW RNRKGAEIIE T IVTIEDKE YPSFNSKSFN LDTFVEDNAT INEIAQQIAD TFAGKREYLN IYVTCFVKIG CAMEVYPSQE MTFDDDDKGK KL FKFEGSA GMHSQKINNA LRTIDTWYPD YTTYEFPIPV ENYGAARSIG IPFRPDTKSF YKLIDRMILK NEDLPIEDKH YVM AILIRG GMFSKKQEK

UniProtKB: Cas7f

-
Macromolecule #4: Non-target strand

MacromoleculeName: Non-target strand / type: dna / ID: 4 / Number of copies: 1 / Classification: DNA
Source (natural)Organism: Selenomonas sp. (bacteria)
Molecular weightTheoretical: 14.233219 KDa
SequenceString:
(DA)(DA)(DA)(DA)(DA)(DG)(DC)(DG)(DG)(DA) (DG)(DA)(DA)(DG)(DT)(DC)(DA)(DT)(DT)(DT) (DA)(DA)(DT)(DA)(DA)(DG)(DG)(DC)(DC) (DA)(DC)(DT)(DG)(DT)(DT)(DA)(DA)(DA)(DA) (DA) (DC)(DC)(DG)(DT)(DA)(DC)

-
Macromolecule #6: Target strand

MacromoleculeName: Target strand / type: dna / ID: 6 / Number of copies: 1 / Classification: DNA
Source (natural)Organism: Selenomonas sp. (bacteria)
Molecular weightTheoretical: 14.094042 KDa
SequenceString:
(DG)(DT)(DA)(DC)(DG)(DG)(DT)(DT)(DT)(DT) (DT)(DA)(DA)(DC)(DA)(DG)(DT)(DG)(DG)(DC) (DC)(DT)(DT)(DA)(DT)(DT)(DA)(DA)(DA) (DT)(DG)(DA)(DC)(DT)(DT)(DC)(DT)(DC)(DC) (DG) (DC)(DT)(DT)(DT)(DT)(DT)

-
Macromolecule #7: crRNA

MacromoleculeName: crRNA / type: rna / ID: 7 / Number of copies: 1
Source (natural)Organism: Selenomonas sp. (bacteria)
Molecular weightTheoretical: 19.440611 KDa
SequenceString:
UUUAGAAGGA GAAGUCAUUU AAUAAGGCCA CUGUUAAAAA GUGUACCGCC GGAUAGGCGG

-
Experimental details

-
Structure determination

Methodcryo EM
Processingsingle particle reconstruction
Aggregation stateparticle

-
Sample preparation

BufferpH: 7.5
VitrificationCryogen name: ETHANE / Chamber humidity: 100 % / Chamber temperature: 277 K

-
Electron microscopy

MicroscopeTFS KRIOS
Image recordingFilm or detector model: FEI FALCON IV (4k x 4k) / Average electron dose: 50.0 e/Å2
Electron beamAcceleration voltage: 300 kV / Electron source: FIELD EMISSION GUN
Electron opticsIllumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD / Nominal defocus max: 1.8 µm / Nominal defocus min: 0.6 µm
Experimental equipment
Model: Titan Krios / Image courtesy: FEI Company

+
Image processing

CTF correctionType: PHASE FLIPPING AND AMPLITUDE CORRECTION
Startup modelType of model: NONE
Final reconstructionResolution.type: BY AUTHOR / Resolution: 1.92 Å / Resolution method: FSC 0.143 CUT-OFF / Software - Name: cryoSPARC / Number images used: 25866
Initial angle assignmentType: NOT APPLICABLE
Final angle assignmentType: NOT APPLICABLE

+
About Yorodumi

-
News

-
Feb 9, 2022. New format data for meta-information of EMDB entries

New format data for meta-information of EMDB entries

  • Version 3 of the EMDB header file is now the official format.
  • The previous official version 1.9 will be removed from the archive.

Related info.:EMDB header

External links:wwPDB to switch to version 3 of the EMDB data model

-
Aug 12, 2020. Covid-19 info

Covid-19 info

URL: https://pdbj.org/emnavi/covid19.php

New page: Covid-19 featured information page in EM Navigator.

Related info.:Covid-19 info / Mar 5, 2020. Novel coronavirus structure data

+
Mar 5, 2020. Novel coronavirus structure data

Novel coronavirus structure data

Related info.:Yorodumi Speices / Aug 12, 2020. Covid-19 info

External links:COVID-19 featured content - PDBj / Molecule of the Month (242)：Coronavirus Proteases

+
Jan 31, 2019. EMDB accession codes are about to change! (news from PDBe EMDB page)

EMDB accession codes are about to change! (news from PDBe EMDB page)

  • The allocation of 4 digits for EMDB accession codes will soon come to an end. Whilst these codes will remain in use, new EMDB accession codes will include an additional digit and will expand incrementally as the available range of codes is exhausted. The current 4-digit format prefixed with “EMD-” (i.e. EMD-XXXX) will advance to a 5-digit format (i.e. EMD-XXXXX), and so on. It is currently estimated that the 4-digit codes will be depleted around Spring 2019, at which point the 5-digit format will come into force.
  • The EM Navigator/Yorodumi systems omit the EMD- prefix.

Related info.:Q: What is EMD? / ID/Accession-code notation in Yorodumi/EM Navigator

External links:EMDB Accession Codes are Changing Soon! / Contact to PDBj

+
Jul 12, 2017. Major update of PDB

Major update of PDB

  • wwPDB released updated PDB data conforming to the new PDBx/mmCIF dictionary.
  • This is a major update changing the version number from 4 to 5, and with Remediation, in which all the entries are updated.
  • In this update, many items about electron microscopy experimental information are reorganized (e.g. em_software).
  • Now, EM Navigator and Yorodumi are based on the updated data.

External links:wwPDB Remediation / Enriched Model Files Conforming to OneDep Data Standards Now Available in the PDB FTP Archive

-
Yorodumi

Thousand views of thousand structures

  • Yorodumi is a browser for structure data from EMDB, PDB, SASBDB, etc.
  • This page is also the successor to EM Navigator detail page, and also detail information page/front-end page for Omokage search.
  • The word "yorodu" (or yorozu) is an old Japanese word meaning "ten thousand". "mi" (miru) is to see.

Related info.:EMDB / PDB / SASBDB / Comparison of 3 databanks / Yorodumi Search / Aug 31, 2016. New EM Navigator & Yorodumi / Yorodumi Papers / Jmol/JSmol / Function and homology information / Changes in new EM Navigator and Yorodumi

Read more