Beta ketoacyl acyl carrier protein synthase II (KASII) from Synechocystis sp.

Experimental Data Snapshot

  • Resolution: 1.54 Å
  • R-Value Free: 0.199 
  • R-Value Work: 0.175 
  • R-Value Observed: 0.175 

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The Crystal Structure of Beta-Ketoacyl-Acyl Carrier Protein Synthase II from Synechocystis Sp. At 1.54 A Resolution and its Relationship to Other Condensing Enzymes

Moche, M.Dehesh, K.Edwards, P.Lindqvist, Y.

(2001) J Mol Biol 305: 491

  • DOI: https://doi.org/10.1006/jmbi.2000.4272
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Condensing enzymes, catalyzing the formation of carbon-carbon bonds in several biosynthetic pathways, have lately been recognized as potential drug targets against cancer and tuberculosis, as crucial for combinatorial biosynthesis of antibiotics and related compounds, and as determinants of plant oil composition. beta-Ketoacyl-ACP synthases (KAS) are the condensing enzymes present in the fatty acid biosynthesis pathway and are able to elongate an acyl chain bound to either co-enzyme A (CoA) or acyl carrier protein (ACP) with a two-carbon unit derived from malonyl-ACP. Several isoforms of KAS with different substrate specificity are present in most species. We have determined the crystal structure of KAS II from Synechocystis sp. PCC 6803 to 1.54 A resolution giving a detailed description of the active site geometry. In order to analyze the structure-function relationships in this class of enzymes in more detail, we have compared all presently known three-dimensional structures of condensing enzymes from different pathways. The comparison reveals that these enzymes can be divided into three structural and functional classes. This classification can be related to variations in the catalytic mechanism and the set of residues in the catalytic site, e.g. due to differences in the nature of the second substrate providing the two-carbon elongation unit. The variation in the acyl-carrier (ACP or CoA) specificity might also be connected to this classification and residues involved in ACP binding in structure class 2 can be suggested based on the comparison. Finally, the two subunits in the dimer contribute differently to formation of the substrate binding-pocket in the three structural classes.

  • Organizational Affiliation

    Department of Medical Biochemistry and Biophysics, Tomtebodavägen 6, Karolinska Institutet, S-171 77, Stockholm, Sweden.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
BETA KETOACYL ACYL CARRIER PROTEIN SYNTHASE II416Synechocystis sp. PCC 6803Mutation(s): 0 
Find proteins for P73283 (Synechocystis sp. (strain PCC 6803 / Kazusa))
Explore P73283 
Go to UniProtKB:  P73283
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP73283
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.54 Å
  • R-Value Free: 0.199 
  • R-Value Work: 0.175 
  • R-Value Observed: 0.175 
  • Space Group: P 31 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 100.8α = 90
b = 100.8β = 90
c = 74.7γ = 120
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2001-01-16
    Type: Initial release
  • Version 1.1: 2011-05-08
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2018-01-17
    Changes: Advisory, Data collection
  • Version 1.4: 2023-12-13
    Changes: Advisory, Data collection, Database references, Other, Refinement description