Biological Assembly 1  

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Global Symmetry: Cyclic - C2  (3D View)
Global Stoichiometry: Homo 2-mer - A2 

Biological assembly 1 assigned by authors and generated by PISA,PQS (software)

Macromolecule Content

• Total Structure Weight: 42727.18 
• Atom Count: 3114 
• Residue Count: 389 
• Unique protein chains: 1

1JWX

Chalcone Synthase--F215S mutant

• DOI: 10.2210/pdb1JWX/pdb

• Classification: TRANSFERASE
• Organism(s): Medicago sativa
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): 1 


• Deposited: 2001-09-05 Released: 2002-07-24 
• Deposition Author(s): Jez, J.M., Bowman, M.E., Noel, J.P.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.63 Å
• R-Value Free: 0.225 
• R-Value Work: 0.190 

Literature

Expanding the biosynthetic repertoire of plant type III polyketide synthases by altering starter molecule specificity.

Jez, J.M., Bowman, M.E., Noel, J.P.

(2002) Proc.Natl.Acad.Sci.USA 99: 5319-5324

• PubMed: 11959984 
• DOI: 10.1073/pnas.082590499


• PubMed Abstract: 
  

Type III polyketide synthases (PKS) generate an array of natural products by condensing multiple acetyl units derived from malonyl-CoA to thioester-linked starter molecules covalently bound in the PKS active site. One strategy adopted by Nature for increasing the functional diversity of these biosynthetic enzymes involves modifying polyketide assembly by altering the preference for starter molecules. Chalcone synthase (CHS) is a ubiquitous plant PKS and the first type III PKS described functionally and structurally. Guided by the three-dimensional structure of CHS, Phe-215 and Phe-265, which are situated at the active site entrance, were targeted for site-directed mutagenesis to diversify CHS activity. The resulting mutants were screened against a panel of aliphatic and aromatic CoA-linked starter molecules to evaluate the degree of starter molecule specificity in CHS. Although wild-type CHS accepts a number of natural CoA thioesters, it does not use N-methylanthraniloyl-CoA as a substrate. Substitution of Phe-215 by serine yields a CHS mutant that preferentially accepts this CoA-thioester substrate to generate a novel alkaloid, namely N-methylanthraniloyltriacetic acid lactone. These results demonstrate that a point mutation in CHS dramatically shifts the molecular selectivity of this enzyme. This structure-based approach to metabolic redesign represents an initial step toward tailoring the biosynthetic activity of plant type III PKS.

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Organizational Affiliation: 

Structural Biology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.

Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
CHALCONE SYNTHASE 2	A	389	Medicago sativa	Mutation(s): 1  Gene Names: CHS2 EC: 2.3.1.74
Find proteins for P30074 (Medicago sativa) Go to UniProtKB:  P30074

Small Molecules

Modified Residues  1 Unique
ID	Chains	Type	Formula	2D Diagram	Parent
CSD	A	L-PEPTIDE LINKING	C3 H7 N O4 S		CYS

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.63 Å
• R-Value Free: 0.225 
• R-Value Work: 0.190 
• Space Group: P 3₂ 2 1

Unit Cell:

Length (Å)	Angle (°)
a = 97.805	α = 90.00
b = 97.805	β = 90.00
c = 65.726	γ = 120.00

Software Package:

Software Name	Purpose
SCALEPACK	data scaling
DENZO	data reduction
REFMAC	refinement

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2001-09-05 
• Released Date: 2002-07-24 
• Deposition Author(s): Jez, J.M., Bowman, M.E., Noel, J.P.

Revision History 

• Version 1.0: 2002-07-24
  Type: Initial release
• Version 1.1: 2008-04-27
  Type: Version format compliance
• Version 1.2: 2011-07-13
  Type: Derived calculations, Version format compliance