6EOK

Crystal structure of E. coli L-asparaginase II

• PDB DOI: https://doi.org/10.2210/pdb6EOK/pdb

• Classification: HYDROLASE
• Organism(s): Escherichia coli K-12
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 2017-10-09 Released: 2018-10-31 
• Deposition Author(s): Cerofolini, L., Giuntini, S., Carlon, A., Ravera, E., Calderone, V., Fragai, M., Parigi, G., Luchinat, C.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.50 Å
• R-Value Free: 
  0.252 (Depositor), 0.250 (DCC) 
• R-Value Work: 
  0.189 (Depositor), 0.190 (DCC) 
• R-Value Observed: 
  0.193 (Depositor) 

Starting Model: experimental

Literature

Characterization of PEGylated Asparaginase: New Opportunities from NMR Analysis of Large PEGylated Therapeutics.

Cerofolini, L., Giuntini, S., Carlon, A., Ravera, E., Calderone, V., Fragai, M., Parigi, G., Luchinat, C.

(2019) Chemistry 25: 1984-1991

• PubMed: 30462348 
• DOI: https://doi.org/10.1002/chem.201804488
• Primary Citation of Related Structures:  
  6EOK


• PubMed Abstract: 
  

  Resonance assignment and structural characterization of pharmacologically relevant proteins promise to improve understanding and safety of these proteins by rational design. However, the PEG coating that is used to evade the immune system also causes these molecules to "evade" the standard structural biology methodologies. We here demonstrate that it is possible to obtain the resonance assignment and a reliable structural model of large PEGylated proteins through an integrated approach encompassing NMR and X-ray crystallography.

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Organizational Affiliation: 

Magnetic Resonance Center (CERM), University of Florence and Consorzio Interuniversitario Risonanze Magnetiche di, Metallo Proteine (CIRMMP), Via L. Sacconi 6, 50019, Sesto Fiorentino, Italy.

Biological Assembly 1  

Global Symmetry: Dihedral - D2  (Explore in 3D)
Global Stoichiometry: Homo 4-mer - A4 

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

Macromolecule Content

• Total Structure Weight: 138.77 kDa 
• Atom Count: 9,528 
• Modelled Residue Count: 1,212 
• Deposited Residue Count: 1,304 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
L-asparaginase 2	A, B, C, D	326	Escherichia coli K-12	Mutation(s): 0  Gene Names: ansB, b2957, JW2924 EC: 3.5.1.1
UniProt
Find proteins for P00805 (Escherichia coli (strain K12)) Explore P00805  Go to UniProtKB:  P00805

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
ZN	E [auth A], F [auth B], G [auth C], H [auth D]	ZINC ION Zn PTFCDOFLOPIGGS-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.50 Å
• R-Value Free:  0.252 (Depositor), 0.250 (DCC) 
• R-Value Work:  0.189 (Depositor), 0.190 (DCC) 
• R-Value Observed: 0.193 (Depositor) 

Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 76.33	α = 90
b = 121.23	β = 90
c = 126.56	γ = 90

Software Package:

Software Name	Purpose
PHENIX	refinement
XDS	data reduction
XSCALE	data scaling
MOLREP	phasing

Structure Validation

Entry History 

Deposition Data

• Released Date: 2018-10-31 
Deposition Author(s): Cerofolini, L., Giuntini, S., Carlon, A., Ravera, E., Calderone, V., Fragai, M., Parigi, G., Luchinat, C.

Revision History  

• Version 1.0: 2018-10-31
  Type: Initial release
  
• Version 1.1: 2018-12-05
  Changes: Data collection, Database references
• Version 1.2: 2019-02-20
  Changes: Data collection, Database references
• Version 1.3: 2024-01-17
  Changes: Data collection, Database references, Derived calculations, Refinement description
• Version 1.4: 2024-11-06
  Changes: Structure summary