5I4B

Erwinia chrysanthemi L-asparaginase E63Q +S254N mutation + L-Aspartic acid

Summary for 5I4B

• Entry DOI: 10.2210/pdb5i4b/pdb
• Related: 5I3Z 5I48
• Descriptor: L-asparaginase, ASPARTIC ACID (3 entities in total)
• Functional Keywords: l-asparaginase, erwinia chrysanthemum, e63q +s254n mutation, l-aspartic acid, hydrolase
• Biological source: Dickeya chrysanthemi (Pectobacterium chrysanthemi)
• Total number of polymer chains: 3
• Total formula weight: 106357.24

Authors

Nguyen, H.A.,Lavie, A. (deposition date: 2016-02-11, release date: 2016-07-06, Last modification date: 2023-09-27)

Primary citation

Nguyen, H.A.,Su, Y.,Lavie, A.
Design and Characterization of Erwinia Chrysanthemi l-Asparaginase Variants with Diminished l-Glutaminase Activity.
J.Biol.Chem., 291:17664-17676, 2016

PubMed Abstract: 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.

PubMed: 27354283
DOI: 10.1074/jbc.M116.728485

Experimental method

X-RAY DIFFRACTION (1.6 Å)