Biological Assembly 1  

 3D View: Structure | Electron Density | Ligand Interaction

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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 (software)

Macromolecule Content

• Total Structure Weight: 164648.69 
• Atom Count: 9455 
• Residue Count: 1462 
• Unique protein chains: 1

3UE0

Crystal structure of Acinetobacter baumannii PBP1a in complex with Aztreonam

• DOI: 10.2210/pdb3UE0/pdb

• Classification: Penicillin-binding protein/Antibiotic
• Organism(s): Acinetobacter baumannii
• Expression System: Escherichia coli


• Deposited: 2011-10-28 Released: 2011-12-14 
• Deposition Author(s): Han, S.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.6 Å
• R-Value Free: 0.241 
• R-Value Work: 0.191 

Literature

Distinctive attributes of beta-lactam target proteins in Acinetobacter baumannii relevant to development of new antibiotics

Han, S., Caspers, N., Zaniewski, R.P., Lacey, B.M., Tomaras, A.P., Feng, X., Geoghegan, K.F., Shanmugasundaram, V.

(2011) J.Am.Chem.Soc. 133: 20536-20545

• PubMed: 22050378 
• DOI: 10.1021/ja208835z
• Primary Citation of Related Structures:  
  3UE3, 3UE1, 3UDX, 3UDI, 3UDF


• PubMed Abstract: 
  

Multi-drug-resistant forms of the Gram-negative pathogen Acinetobacter baumannii are an emerging threat to human health and further complicate the general problem of treating serious bacterial infections. Meeting this challenge requires an improved understanding of the relationships between the structures of major therapeutic targets in this organism and the activity levels exhibited against it by different antibiotics. Here we report the first crystal structures of A. baumannii penicillin-binding proteins (PBPs) covalently inactivated by four β-lactam antibiotics. We also relate the results to kinetic, biophysical, and computational data. The structure of the class A protein PBP1a was solved in apo form and for its covalent conjugates with benzyl penicillin, imipenem, aztreonam, and the siderophore-conjugated monocarbam MC-1. It included a novel domain genetically spliced into a surface loop of the transpeptidase domain that contains three conserved loops. Also reported here is the first high-resolution structure of the A. baumannii class B enzyme PBP3 in apo form. Comparison of this structure with that of MC-1-derivatized PBP3 of Pseudomonas aeruginosa identified differences between these orthologous proteins in A. baumannii and P. aeruginosa. Thermodynamic analyses indicated that desolvation effects in the PBP3 ligand-binding sites contributed significantly to the thermal stability of the enzyme-antibiotic covalent complexes. Across a significant range of values, they correlated well with results from studies of inactivation kinetics and the protein structures. The structural, biophysical, and computational data help rationalize differences in the functional performance of antibiotics against different protein targets and can be used to guide the design of future agents.

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Organizational Affiliation: 

Pfizer Worldwide Research, Eastern Point Road, Groton, Connecticut 06340, USA. [e-mail]

Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
Penicillin-binding protein 1a	A, B	731	Acinetobacter baumannii	Mutation(s): 0  Gene Names: ponA
Find proteins for G1C794 (Acinetobacter baumannii) Go to UniProtKB:  G1C794

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram & Interactions
AZR	A, B	2-({[(1Z)-1-(2-amino-1,3-thiazol-4-yl)-2-oxo-2-{[(2S,3S)-1-oxo-3-(sulfoamino)butan-2-yl]amino}ethylidene]amino}oxy)-2-methylpropanoic acid AZTREONAM, open form C13 H19 N5 O8 S2 OEVQTUTXOVDNJO-GEEOIBTQSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.6 Å
• R-Value Free: 0.241 
• R-Value Work: 0.191 
• Space Group: P 2₁ 2₁ 2

Unit Cell:

Length (Å)	Angle (°)
a = 119.080	α = 90.00
b = 242.570	β = 90.00
c = 49.310	γ = 90.00

Software Package:

Software Name	Purpose
BUSTER	refinement
PHASER	phasing
SCALEPACK	data scaling
HKL-2000	data collection
HKL-2000	data reduction

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2011-10-28 
• Released Date: 2011-12-14 
• Deposition Author(s): Han, S.

Revision History 

• Version 1.0: 2011-12-14
  Type: Initial release
• Version 1.1: 2013-06-26
  Type: Database references