9IYW | pdb_00009iyw

Crystal structure of chimeric KSQ-AT didomain


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 
    0.246 (Depositor), 0.249 (DCC) 
  • R-Value Work: 
    0.201 (Depositor), 0.208 (DCC) 
  • R-Value Observed: 
    0.204 (Depositor) 

Starting Model: in silico
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wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Ancestral sequence reconstruction as a tool for structural analysis of modular polyketide synthases.

Chisuga, T.Takinami, S.Liao, Z.Karasawa, M.Adachi, N.Kawasaki, M.Moriya, T.Senda, T.Terada, T.Kudo, F.Eguchi, T.Nakano, S.Ito, S.Miyanaga, A.

(2025) Nat Commun 16: 6847-6847

  • DOI: https://doi.org/10.1038/s41467-025-62168-0
  • Primary Citation of Related Structures:  
    9IYW, 9JJ9, 9JJB

  • PubMed Abstract: 

    Modular polyketide synthases (PKSs) are large multi-domain enzymes critical for the biosynthesis of polyketide antibiotics. However, challenges with structural analysis limits our mechanistic understanding of modular PKSs. In this report, we explore the potential of ancestral sequence reconstruction (ASR) for structure analysis of target proteins. As a model, we focus on the FD-891 PKS loading module composed of ketosynthase-like decarboxylase (KS Q ), acyltransferase (AT) and acyl carrier protein (ACP) domains. We construct a KS Q AncAT chimeric didomain by replacing the native AT with an ancestral AT (AncAT) using ASR. After confirming that KS Q AncAT chimeric didomain retains similar enzymatic function to the native KS Q AT didomain, we successfully determine a high-resolution crystal structure of the KS Q AncAT chimeric didomain and cryo-EM structures of the KS Q -ACP complex. These cryo-EM structures, which could not be determined for the native protein, exemplify the utility of ASR to enable cryo-EM single-particle analysis. Our findings demonstrate that integrating ASR with structural analysis provides deeper mechanistic insight into modular PKSs. Furthermore, applying ASR to a partial region of the targeted multi-domain proteins could expand the potential of ASR and may serve as a valuable framework for investigating the structure and function of various multi-domain proteins.


  • Organizational Affiliation
    • Graduate School of Integrated Pharmaceutical and Nutritional Science, University of Shizuoka, Shizuoka, Japan.

Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Polyketide synthase,GfsA KSQ-AncAT chimeric protein922Streptomyces graminofacienssynthetic constructMutation(s): 0 
Gene Names: gfsA
EC: 2.3.1 (UniProt), 4.1.1 (UniProt)
UniProt
Find proteins for E0D202 (Streptomyces halstedii)
Explore E0D202 
Go to UniProtKB:  E0D202
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupE0D202
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
NA
Query on NA

Download Ideal Coordinates CCD File 
B [auth A]SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free:  0.246 (Depositor), 0.249 (DCC) 
  • R-Value Work:  0.201 (Depositor), 0.208 (DCC) 
  • R-Value Observed: 0.204 (Depositor) 
Space Group: P 31 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 76.065α = 90
b = 76.065β = 90
c = 352.97γ = 120
Software Package:
Software NamePurpose
REFMACrefinement
XDSdata reduction
Aimlessdata scaling
MOLREPphasing
Cootmodel building

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Japan Society for the Promotion of Science (JSPS)Japan20H02911

Revision History  (Full details and data files)

  • Version 1.0: 2025-08-06
    Type: Initial release
  • Version 1.1: 2025-08-13
    Changes: Database references