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 9KQ3 | pdb_00009kq3

Cryo-EM structure of Saccharomyces cerevisiae Mitochondrial Respiratory Complex II in pydiflumetofen-bound state


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.23 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

wwPDB Validation 3D Report Full Report

Validation slider image for 9KQ3

This is version 1.2 of the entry. See complete history. 

Literature

Cryo-EM structure of the yeast Saccharomyces cerevisiae SDH provides a template for eco-friendly fungicide discovery.

Li, Z.W., Huang, Y.H., Wei, G., Lu, Z.W., Wang, Y.X., Cui, G.R., Wang, J.Y., Yu, X.H., Fu, Y.X., Fan, E.D., Wu, Q.Y., Zhu, X.L., Ye, Y., Yang, G.F.

(2025) Nat Commun 16: 8936-8936

  • DOI: https://doi.org/10.1038/s41467-025-64001-0
  • Primary Citation Related Structures: 
    9KPS, 9KPT, 9KQ3, 9LIG

  • PubMed Abstract: 

    Succinate dehydrogenase (SDH) is a key fungicidal target, but rational inhibitors design has been impeded by the lack of fungal SDH structure. Here, we show the cryo-EM structure of SDH from Saccharomyces cerevisiae (ScSDH) in apo (3.36 Å) and ubiquinone-1-bound (3.25 Å) states, revealing subunits architecture and quinone-binding sites (Q p ). ScSDH is classified as a heme-deficient type-D SDH, utilizing conserved redox centers (FAD, [2Fe-2S], [4Fe-4S] and [3Fe-4S] clusters) for electron transfer. A 3.23 Å structure with pydiflumetofen (PYD) identified critical interactions, including hydrogen bonds with Trp_SDHB194 and Tyr_SDHD120, and a cation-π interaction with Arg_SDHC97. Leveraging this, we designed a SDH inhibitor E8 (enprocymid), exhibiting significant fungicidal activity (K i  = 0.019 μM) and reduced zebrafish toxicity (LC 50 (96 h) = 1.01 mg a.i./L). This study elucidates the structure of fungal SDH and demonstrates the potential of ScSDH for rational design of next-generation fungicides, addressing fungal resistance and environmental toxicity in agriculture.


  • Organizational Affiliation: 
    • State Key Laboratory of Green Pesticide, International Joint Research Center for Intelligent Biosensor Technology and Health, Central China Normal University, Wuhan, P.R. China.

Macromolecule Content 

  • Total Structure Weight: 126.28 kDa 
  • Atom Count: 8,819 
  • Modeled Residue Count: 1,106 
  • Deposited Residue Count: 1,106 
  • Unique protein chains: 4

Macromolecules

Find similar proteins by:|  3D Structure
Entity ID: 1
MoleculeChains  Sequence LengthOrganismDetailsImage
Succinate dehydrogenase [ubiquinone] flavoprotein subunit, mitochondrial596Saccharomyces cerevisiaeMutation(s): 0 
EC: 1.3.5.1
UniProt
Find proteins for Q00711 (Saccharomyces cerevisiae (strain ATCC 204508 / S288c))
Explore Q00711 
Go to UniProtKB:  Q00711
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ00711
Sequence Annotations
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Reference Sequence
Find similar proteins by:|  3D Structure
Entity ID: 2
MoleculeChains  Sequence LengthOrganismDetailsImage
Succinate dehydrogenase [ubiquinone] iron-sulfur subunit, mitochondrial236Saccharomyces cerevisiaeMutation(s): 0 
EC: 1.3.5.1
UniProt
Find proteins for P21801 (Saccharomyces cerevisiae (strain ATCC 204508 / S288c))
Explore P21801 
Go to UniProtKB:  P21801
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP21801
Sequence Annotations
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Reference Sequence
Find similar proteins by:|  3D Structure
Entity ID: 3
MoleculeChains  Sequence LengthOrganismDetailsImage
Sdh3p143Saccharomyces cerevisiaeMutation(s): 0 
UniProt
Find proteins for P33421 (Saccharomyces cerevisiae (strain ATCC 204508 / S288c))
Explore P33421 
Go to UniProtKB:  P33421
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP33421
Sequence Annotations
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Reference Sequence
Find similar proteins by:|  3D Structure
Entity ID: 4
MoleculeChains  Sequence LengthOrganismDetailsImage
Succinate dehydrogenase [ubiquinone] cytochrome b small subunit, mitochondrial131Saccharomyces cerevisiaeMutation(s): 0 
UniProt
Find proteins for P37298 (Saccharomyces cerevisiae (strain ATCC 204508 / S288c))
Explore P37298 
Go to UniProtKB:  P37298
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP37298
Sequence Annotations
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Reference Sequence

Small Molecules

Ligands 6 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
FAD

Query on FAD



Download:Ideal Coordinates CCD File
E [auth A]FLAVIN-ADENINE DINUCLEOTIDE
C27 H33 N9 O15 P2
VWWQXMAJTJZDQX-UYBVJOGSSA-N
PEE

Query on PEE



Download:Ideal Coordinates CCD File
J [auth D]1,2-dioleoyl-sn-glycero-3-phosphoethanolamine
C41 H78 N O8 P
MWRBNPKJOOWZPW-NYVOMTAGSA-N
A1EE4
(Subject of Investigation/LOI)

Query on A1EE4



Download:Ideal Coordinates CCD File
I [auth C]Pydiflumetofen
C16 H16 Cl3 F2 N3 O2
DGOAXBPOVUPPEB-QMMMGPOBSA-N
SF4

Query on SF4



Download:Ideal Coordinates CCD File
G [auth B]IRON/SULFUR CLUSTER
Fe4 S4
LJBDFODJNLIPKO-UHFFFAOYSA-N
F3S

Query on F3S



Download:Ideal Coordinates CCD File
H [auth B]FE3-S4 CLUSTER
Fe3 S4
FCXHZBQOKRZXKS-UHFFFAOYSA-N
FES

Query on FES



Download:Ideal Coordinates CCD File
F [auth B]FE2/S2 (INORGANIC) CLUSTER
Fe2 S2
NIXDOXVAJZFRNF-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.23 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

Structure Validation

View Full Validation Report



Entry History 

& Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Natural Science Foundation of China (NSFC)China--

Revision History  (Full details and data files)

  • Version 1.0: 2025-09-03
    Type: Initial release
  • Version 1.1: 2025-10-22
    Changes: Data collection, Database references
  • Version 1.2: 2026-08-12
    Type: Remediation
    Reason: Metalloprotein remediation
    Changes: Advisory, Data collection, Derived calculations, Structure summary