5I4B image
Deposition Date 2016-02-11
Release Date 2016-07-06
Last Version Date 2023-09-27
Entry Detail
PDB ID:
5I4B
Keywords:
Title:
Erwinia chrysanthemi L-asparaginase E63Q +S254N mutation + L-Aspartic acid
Biological Source:
Source Organism:
Host Organism:
Method Details:
Experimental Method:
Resolution:
1.60 Å
R-Value Free:
0.18
R-Value Work:
0.15
R-Value Observed:
0.15
Space Group:
I 2 2 2
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:L-asparaginase
Gene (Uniprot):ansB
Mutations:E63Q, S254N
Chain IDs:A, B, C
Chain Length:328
Number of Molecules:3
Biological Source:Dickeya chrysanthemi
Primary Citation
Design and Characterization of Erwinia Chrysanthemi l-Asparaginase Variants with Diminished l-Glutaminase Activity.
J.Biol.Chem. 291 17664 17676 (2016)
PMID: 27354283 DOI: 10.1074/jbc.M116.728485

Abstact

Current FDA-approved l-asparaginases also possess significant l-glutaminase activity, which correlates with many of the toxic side effects of these drugs. Therefore, l-asparaginases with reduced l-glutaminase activity are predicted to be safer. We exploited our recently described structures of the Erwinia chrysanthemi l-asparaginase (ErA) to inform the design of mutants with diminished ability to hydrolyze l-glutamine. Structural analysis of these variants provides insight into the molecular basis for the increased l-asparagine specificity. A primary role is attributed to the E63Q mutation that acts to hinder the correct positioning of l-glutamine but not l-asparagine. The substitution of Ser-254 with either an asparagine or a glutamine increases the l-asparagine specificity but only when combined with the E63Q mutation. The A31I mutation reduces the substrate Km value; this is a key property to allow the required therapeutic l-asparagine depletion. Significantly, an ultra-low l-glutaminase ErA variant maintained its cell killing ability. By diminishing the l-glutaminase activity of these highly active l-asparaginases, our engineered ErA variants hold promise as l-asparaginases with fewer side effects.

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Primary Citation of related structures