9UTW | pdb_00009utw

Structure of dimeric FKS1 in complex with tRNA


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 2.96 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

wwPDB Validation 3D Report Full Report

Validation slider image for 9UTW

This is version 1.1 of the entry. See complete history

Literature

Structural-guided identification of two modulators of beta-1,3-glucan synthase FKS1.

Li, J.Li, J.Zhu, A.Dai, X.Liu, J.Liu, H.Xia, Z.Dong, Y.Qian, W.Dai, L.Guo, L.Yan, C.Deng, D.Luo, Y.Wang, X.

(2025) Nat Commun 17: 591-591

  • DOI: https://doi.org/10.1038/s41467-025-67293-4
  • Primary Citation Related Structures: 
    9UTU, 9UTW

  • PubMed Abstract: 

    FKS1 is a β-1,3-glucan synthase critical for fungal cell wall formation and a target for antifungal drugs such as echinocandin and ibrexafungerp. However, the mechanisms regulating FKS1 activity remain largely unknown. Here, we reveal that transfer RNA (tRNA) acts as an endogenous inhibitor, whereas GSR1 functions as a stabilizer of FKS1. The cryo-EM structure of FKS1 adopts a tRNA-mediated homodimer configuration, representing a quiescent state of β-1,3-glucan synthase. Unexpectedly, the copurified endogenous tRNA is identified as a potent inhibitor that suppresses FKS1 activity. Moreover, high-resolution cryo-EM density analysis enable the identification of GSR1 as an additional binding partner of FKS1. Mutagenesis experiments confirm the interaction between FKS1 and GSR1. Evolutionarily conserved GSR1 is found to increase the stability of FKS1 in β-1,3-glucan biosynthesis. Collectively, our findings identify both tRNA and GSR1 as intrinsic modulators of β-1,3-glucan biosynthesis, thereby providing opportunities for the further development of FKS1-targeted antifungal drugs.


  • Organizational Affiliation
    • Department of Obstetrics, Key Laboratory of Birth Defects and Related Disease of Women and Children of MOE, State Key Laboratory of Biotherapy, West China Second Hospital, Sichuan University, Chengdu, China.

Macromolecule Content 

  • Total Structure Weight: 508.99 kDa 
  • Atom Count: 25,408 
  • Modeled Residue Count: 2,930 
  • Deposited Residue Count: 4,222 
  • Unique protein chains: 2
  • Unique nucleic acid chains: 1

Macromolecules


Find similar proteins by:|  3D Structure
Entity ID: 1
MoleculeChains  Sequence LengthOrganismDetailsImage
Uncharacterized protein YMR295CA [auth C],
B [auth G]
197Saccharomyces cerevisiaeMutation(s): 0 
UniProt
Find proteins for Q03559 (Saccharomyces cerevisiae (strain ATCC 204508 / S288c))
Explore Q03559 
Go to UniProtKB:  Q03559
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ03559
Sequence Annotations
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Reference Sequence
Find similar proteins by:|  3D Structure
Entity ID: 2
MoleculeChains  Sequence LengthOrganismDetailsImage
1,3-beta-glucan synthase component FKS1C [auth H],
D [auth B]
1,876Saccharomyces cerevisiaeMutation(s): 0 
EC: 2.4.1.34
UniProt
Find proteins for P38631 (Saccharomyces cerevisiae (strain ATCC 204508 / S288c))
Explore P38631 
Go to UniProtKB:  P38631
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP38631
Sequence Annotations
Expand
Reference Sequence
Find similar nucleic acids by:  (by identity cutoff) 
Entity ID: 3
MoleculeChains LengthOrganismImage
tRNAE [auth A]76Saccharomyces cerevisiae
Sequence Annotations
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Reference Sequence

Oligosaccharides

Help  
Entity ID: 4
MoleculeChains Length2D Diagram GlycosylationD Interactions
beta-D-glucopyranose-(1-3)-beta-D-glucopyranose-(1-3)-beta-D-glucopyranoseF [auth J]3N/A
Glycosylation Resources
GlyTouCan: G00024MO
GlyCosmos: G00024MO
GlyGen: G00024MO
Entity ID: 5
MoleculeChains Length2D Diagram GlycosylationD Interactions
beta-D-glucopyranose-(1-3)-beta-D-glucopyranoseG [auth D]2N/A
Glycosylation Resources
GlyTouCan: G36535HU
GlyCosmos: G36535HU

Small Molecules

Ligands 8 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
PEF
(Subject of Investigation/LOI)

Query on PEF



Download:Ideal Coordinates CCD File
KA [auth B],
Q [auth H]
DI-PALMITOYL-3-SN-PHOSPHATIDYLETHANOLAMINE
C37 H74 N O8 P
SLKDGVPOSSLUAI-PGUFJCEWSA-N
XKP
(Subject of Investigation/LOI)

Query on XKP



Download:Ideal Coordinates CCD File
JA [auth B],
P [auth H]
(11R,14S)-17-amino-14-hydroxy-8,14-dioxo-9,13,15-trioxa-14lambda~5~-phosphaheptadecan-11-yl decanoate
C23 H46 N O8 P
VYUSSAVVRCGYLY-OAQYLSRUSA-N
DCR
(Subject of Investigation/LOI)

Query on DCR



Download:Ideal Coordinates CCD File
PA [auth B],
V [auth H]
icosanoic acid
C20 H40 O2
VKOBVWXKNCXXDE-UHFFFAOYSA-N
PLM
(Subject of Investigation/LOI)

Query on PLM



Download:Ideal Coordinates CCD File
LA [auth B]
MA [auth B]
NA [auth B]
OA [auth B]
QA [auth B]
LA [auth B],
MA [auth B],
NA [auth B],
OA [auth B],
QA [auth B],
R [auth H],
RA [auth B],
S [auth H],
SA [auth B],
T [auth H],
TA [auth B],
U [auth H],
UA [auth B],
W [auth H],
X [auth H],
Y [auth H]
PALMITIC ACID
C16 H32 O2
IPCSVZSSVZVIGE-UHFFFAOYSA-N
D10
(Subject of Investigation/LOI)

Query on D10



Download:Ideal Coordinates CCD File
EA [auth B],
M [auth H]
DECANE
C10 H22
DIOQZVSQGTUSAI-UHFFFAOYSA-N
DD9
(Subject of Investigation/LOI)

Query on DD9



Download:Ideal Coordinates CCD File
AA [auth B]
BA [auth B]
CA [auth B]
DA [auth B]
I [auth H]
AA [auth B],
BA [auth B],
CA [auth B],
DA [auth B],
I [auth H],
J [auth H],
K [auth H],
L [auth H]
nonane
C9 H20
BKIMMITUMNQMOS-UHFFFAOYSA-N
HP6
(Subject of Investigation/LOI)

Query on HP6



Download:Ideal Coordinates CCD File
FA [auth B]
GA [auth B]
HA [auth B]
IA [auth B]
N [auth H]
FA [auth B],
GA [auth B],
HA [auth B],
IA [auth B],
N [auth H],
O [auth H]
HEPTANE
C7 H16
IMNFDUFMRHMDMM-UHFFFAOYSA-N
MG
(Subject of Investigation/LOI)

Query on MG



Download:Ideal Coordinates CCD File
H,
Z [auth B]
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N

Biologically Interesting Molecules (External Reference) 

1 Unique

Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 2.96 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: 2025-12-17
    Type: Initial release
  • Version 1.1: 2026-01-28
    Changes: Data collection, Database references