4ECA

ASPARAGINASE FROM E. COLI, MUTANT T89V WITH COVALENTLY BOUND ASPARTATE

Summary for 4ECA

• Entry DOI: 10.2210/pdb4eca/pdb
• Descriptor: L-ASPARAGINE AMIDOHYDROLASE (2 entities in total)
• Functional Keywords: hydrolase, acyl-enzyme intermediate, threonine amidohydrolase
• Biological source: Escherichia coli
• Total number of polymer chains: 4
• Total formula weight: 138959.70

Authors

Palm, G.J.,Lubkowski, J.,Wlodawer, A. (deposition date: 1997-02-21, release date: 1997-06-16, Last modification date: 2023-08-09)

Primary citation

Palm, G.J.,Lubkowski, J.,Derst, C.,Schleper, S.,Rohm, K.H.,Wlodawer, A.
A covalently bound catalytic intermediate in Escherichia coli asparaginase: crystal structure of a Thr-89-Val mutant.
FEBS Lett., 390:211-216, 1996

PubMed Abstract: Escherichia coli asparaginase II catalyzes the hydrolysis of L-asparagine to L-aspartate via a threonine-bound acyl-enzyme intermediate. A nearly inactive mutant in which one of the active site threonines, Thr-89, was replaced by valine was constructed, expressed, and crystallized. Its structure, solved at 2.2 A resolution, shows high overall similarity to the wild-type enzyme, but an aspartyl moiety is covalently bound to Thr-12, resembling a reaction intermediate. Kinetic analysis confirms the deacylation deficiency, which is also explained on a structural basis. The previously identified oxyanion hole is described in more detail.

PubMed: 8706862
DOI: 10.1016/0014-5793(96)00660-6

Experimental method

X-RAY DIFFRACTION (2.2 Å)