PfaC Keto synthase-Chain length factor

Experimental Data Snapshot

  • Resolution: 1.85 Å
  • R-Value Free: 0.190 
  • R-Value Work: 0.163 
  • R-Value Observed: 0.165 

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This is version 2.1 of the entry. See complete history


Structure and Mechanism of the Ketosynthase-Chain Length Factor Didomain from a Prototypical Polyunsaturated Fatty Acid Synthase.

Santin, O.Yuet, K.Khosla, C.Moncalian, G.

(2020) Biochemistry 59: 4735-4743

  • DOI: https://doi.org/10.1021/acs.biochem.0c00785
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Long-chain polyunsaturated fatty acids (LC-PUFAs) are essential ingredients of the human diet. They are synthesized by LC-PUFA synthases (PFASs) expressed in marine bacteria and other organisms. PFASs are large enzyme complexes that are homologous to mammalian fatty acid synthases and microbial polyketide synthases. One subunit of each PFAS harbors consecutive ketosynthase (KSc) and chain length factor (CLF) domains that collectively catalyze the elongation of a nascent fatty acyl chain via iterative carbon-carbon bond formation. We report the X-ray crystal structure of the KS-CLF didomain from a well-studied PFAS in Moritella marina . Our structure, in combination with biochemical analysis, provides a foundation for understanding the mechanism of substrate recognition and chain length control by the KS-CLF didomain as well as its interaction with a cognate acyl carrier protein partner.

  • Organizational Affiliation

    Departamento de Biología Molecular, Universidad de Cantabria and Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), CSIC-Universidad de Cantabria, E-39011 Santander, Spain.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
ORF101,014Moritella marinaMutation(s): 0 
Find proteins for Q9RA19 (Moritella marina)
Explore Q9RA19 
Go to UniProtKB:  Q9RA19
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9RA19
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on MG

Download Ideal Coordinates CCD File 
Experimental Data & Validation

Experimental Data

  • Resolution: 1.85 Å
  • R-Value Free: 0.190 
  • R-Value Work: 0.163 
  • R-Value Observed: 0.165 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 78.24α = 90
b = 90.83β = 90
c = 132.42γ = 90
Software Package:
Software NamePurpose
MOSFLMdata reduction
SCALAdata scaling

Structure Validation

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Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
Spanish Ministry of Science, Innovation, and UniversitiesSpainPGC2018-093885-B-I00

Revision History  (Full details and data files)

  • Version 1.0: 2020-08-26
    Type: Initial release
  • Version 2.0: 2021-02-24
    Changes: Advisory, Atomic model, Author supporting evidence, Data collection, Database references, Derived calculations, Experimental preparation, Other, Refinement description, Structure summary
  • Version 2.1: 2024-01-24
    Changes: Data collection, Database references, Refinement description