spacer
spacer

PDBsum entry 3ale

Go to PDB code: 
protein Protein-protein interface(s) links
Transferase PDB id
3ale
Jmol
Contents
Protein chains
369 a.a. *
Waters ×125
* Residue conservation analysis
PDB id:
3ale
Name: Transferase
Title: A type iii polyketide synthase that produces diarylheptanoid
Structure: Os07g0271500 protein. Chain: a, b, c, d. Synonym: curcuminoid synthase, putative chalcone synthase. Engineered: yes
Source: Oryza sativa. Rice. Organism_taxid: 39947. Strain: japonica. Gene: oj1001_c01.122, osjnbb0002j01.6, os07g0271500. Expressed in: escherichia coli. Expression_system_taxid: 562.
Resolution:
2.50Å     R-factor:   0.221     R-free:   0.272
Authors: H.Morita,R.Kato,S.Sugio,I.Abe
Key ref: H.Morita et al. (2010). Structural basis for the one-pot formation of the diarylheptanoid scaffold by curcuminoid synthase from Oryza sativa. Proc Natl Acad Sci U S A, 107, 19778-19783. PubMed id: 21041675
Date:
03-Aug-10     Release date:   03-Nov-10    
PROCHECK
Go to PROCHECK summary
 Headers
 References

Protein chains
Pfam   ArchSchema ?
Q8LIL0  (CUS_ORYSJ) -  Bisdemethoxycurcumin synthase
Seq:
Struc:
402 a.a.
369 a.a.*
Key:    PfamA domain  Secondary structure  CATH domain
* PDB and UniProt seqs differ at 1 residue position (black cross)

 Enzyme reactions 
   Enzyme class: E.C.2.3.1.211  - Bisdemethoxycurcumin synthase.
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]
      Reaction: 2 4-coumaroyl-CoA + malonyl-CoA + H2O = 3 CoA + bisdemethoxycurcumin + 2 CO2
2 × 4-coumaroyl-CoA
+ malonyl-CoA
+ H(2)O
= 3 × CoA
+ bisdemethoxycurcumin
+ 2 × CO(2)
Molecule diagrams generated from .mol files obtained from the KEGG ftp site
 Gene Ontology (GO) functional annotation 
  GO annot!
  Biological process     metabolic process   3 terms 
  Biochemical function     catalytic activity     5 terms  

 

 
    reference    
 
 
Proc Natl Acad Sci U S A 107:19778-19783 (2010)
PubMed id: 21041675  
 
 
Structural basis for the one-pot formation of the diarylheptanoid scaffold by curcuminoid synthase from Oryza sativa.
H.Morita, K.Wanibuchi, H.Nii, R.Kato, S.Sugio, I.Abe.
 
  ABSTRACT  
 
Curcuminoid synthase (CUS) from Oryza sativa is a plant-specific type III polyketide synthase (PKS) that catalyzes the remarkable one-pot formation of the C(6)-C(7)-C(6) diarylheptanoid scaffold of bisdemethoxycurcumin, by the condensation of two molecules of 4-coumaroyl-CoA and one molecule of malonyl-CoA. The crystal structure of O. sativa CUS was solved at 2.5-Å resolution, which revealed a unique, downward expanding active-site architecture, previously unidentified in the known type III PKSs. The large active-site cavity is long enough to accommodate the two C(6)-C(3) coumaroyl units and one malonyl unit. Furthermore, the crystal structure indicated the presence of a putative nucleophilic water molecule, which forms hydrogen bond networks with Ser351-Asn142-H(2)O-Tyr207-Glu202, neighboring the catalytic Cys174 at the active-site center. These observations suggest that CUS employs unique catalytic machinery for the one-pot formation of the C(6)-C(7)-C(6) scaffold. Thus, CUS utilizes the nucleophilic water to terminate the initial polyketide chain elongation at the diketide stage. Thioester bond cleavage of the enzyme-bound intermediate generates 4-coumaroyldiketide acid, which is then kept within the downward expanding pocket for subsequent decarboxylative condensation with the second 4-coumaroyl-CoA starter, to produce bisdemethoxycurcumin. The structure-based site-directed mutants, M265L and G274F, altered the substrate and product specificities to accept 4-hydroxyphenylpropionyl-CoA as the starter to produce tetrahydrobisdemethoxycurcumin. These findings not only provide a structural basis for the catalytic machinery of CUS but also suggest further strategies toward expanding the biosynthetic repertoire of the type III PKS enzymes.