Biological Assembly 1  

 3D View: Structure | Ligand Interaction

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: 34.73 kDa 
• Atom Count: 2618 
• Residue Count: 317 
• Unique protein chains: 1

1HNH

CRYSTAL STRUCTURE OF BETA-KETOACYL-ACP SYNTHASE III + DEGRADED FORM OF ACETYL-COA

• DOI: 10.2210/pdb1HNH/pdb

• Classification: TRANSFERASE
• Organism(s): Escherichia coli
• Expression System: Escherichia coli
• Mutation(s): Yes 


• Deposited: 2000-12-07 Released: 2000-12-27 
• Deposition Author(s): Qiu, X., Janson, C.A., Smith, W.W., Head, M., Lonsdale, J., Konstantinidis, A.K.

---

Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.90 Å
• R-Value Free: 0.274 
• R-Value Work: 0.221 

Literature

Refined structures of beta-ketoacyl-acyl carrier protein synthase III.

Qiu, X., Janson, C.A., Smith, W.W., Head, M., Lonsdale, J., Konstantinidis, A.K.

(2001) J Mol Biol 307: 341-356

• PubMed: 11243824 
• DOI: 10.1006/jmbi.2000.4457
• Primary Citation of Related Structures:  
  1HNK, 1HNJ, 1HNH, 1HND


• PubMed Abstract: 
  

beta-Ketoacyl-acyl carrier protein synthase III (FabH) is a condensing enzyme that plays central roles in fatty acid biosynthesis. Three-dimensional structures of E. coli FabH in the presence and absence of ligands have been refined to 1.46 A resolution. The structures of improved accuracy revealed detailed interactions involved in ligand binding. These structures also provided new insights into the FabH mechanism, e.g. the possible role of a water or hydroxyl anion in Cys112 deprotonation. A structure of the apo enzyme uncovered large conformational changes in the active site, exemplified by the disordering of four essential loops (84-86, 146-152, 185-217 and 305-307) and the movement of catalytic residues (Cys112 and His244). The disordering of the loops leads to greater than 50 % reduction in the FabH dimer interface, suggesting a dynamic nature for an unusually large portion of the dimer interface. The existence of a large solvent-accessible channel in the dimer interface as well as two cis-peptides (cis-Pro88 and cis-Phe308) in two of the disordered loops may explain the observed structural instabilities.

---

Related Citations: 

• Crystal Structure of Beta-Ketoacyl-Acyl Carrier Protein Synthase III. A Key Condensing Enzyme in Bacterial Fatty Acid Biosynthesis
  Qiu, X., Janson, C.A., Konstantinidis, A.K., Nwagwu, S., Silverman, C., Smith, W.W., Khandekar, S.K., Lonsdale, J., Abdel-Meguid, S.S.
  (1999) J Biol Chem 274: 36465

---

Organizational Affiliation: 

Department of Structural Biology, SmithKline Beecham Pharmaceuticals, King of Prussia, PA 19406, USA. [e-mail]

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
BETA-KETOACYL-ACYL CARRIER PROTEIN SYNTHASE III	A	317	Escherichia coli	Mutation(s): 9  EC: 2.3.1.41 (PDB Primary Data), 2.3.1.180 (UniProt)
Find proteins for P0A6R0 (Escherichia coli (strain K12)) Explore P0A6R0  Go to UniProtKB:  P0A6R0

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
COA	A	COENZYME A C21 H36 N7 O16 P3 S RGJOEKWQDUBAIZ-IBOSZNHHSA-N

Modified Residues  2 Unique
ID	Chains	Type	Formula	2D Diagram	Parent
MSE	A	L-PEPTIDE LINKING	C5 H11 N O2 Se		MET
SCY	A	L-PEPTIDE LINKING	C5 H9 N O3 S		CYS

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.90 Å
• R-Value Free: 0.274 
• R-Value Work: 0.221 
• Space Group: P 4₁ 2₁ 2

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 72.45	α = 90
b = 72.45	β = 90
c = 102.8	γ = 90

Software Package:

Software Name	Purpose
SOLVE	phasing
CNS	refinement
DENZO	data reduction
SCALEPACK	data scaling

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2000-12-07 
• Released Date: 2000-12-27 
Deposition Author(s): Qiu, X., Janson, C.A., Smith, W.W., Head, M., Lonsdale, J., Konstantinidis, A.K.

Revision History 

• Version 1.0: 2000-12-27
  Type: Initial release
  
• Version 1.1: 2008-04-27
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Derived calculations, Version format compliance