1t3m
Structure of the isoaspartyl peptidase with L-asparaginase activity from E. coli
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OverviewOverview
The crystal structure of the Escherichia coli enzyme (EcAIII) with, isoaspartyl dipeptidase and L-asparaginase activity has been solved and, refined to a resolution of 1.65 angstroms, with crystallographic R-factor, and Rfree values of 0.178 and 0.209, respectively. EcAIII belongs to the, family of N-terminal hydrolases. The amino-acid sequence of EcAIII is, homologous to those of putative asparaginases from plants. The structure, of EcAIII is similar to the structures of glycosylasparaginases. The, mature and catalytically active form of EcAIII is a heterotetramer, consisting of two alpha-subunits and two beta-subunits. Both of the, equivalent active sites present in the EcAIII tetramer is assisted by a, metal-binding site. The metal cations, modelled here as Na+, have not, previously been observed in glycosylasparaginases. This reported structure, helps to explain the inability of EcAIII and other plant-type, asparaginases to hydrolyze N4-(beta-N-acetylglucosaminyl)-L-asparagine, the substrate of glycosylasparaginases.
About this StructureAbout this Structure
1T3M is a Protein complex structure of sequences from Escherichia coli with NA and NO3 as ligands. Active as Asparaginase, with EC number 3.5.1.1 Full crystallographic information is available from OCA.
ReferenceReference
Structure of the isoaspartyl peptidase with L-asparaginase activity from Escherichia coli., Prahl A, Pazgier M, Hejazi M, Lockau W, Lubkowski J, Acta Crystallogr D Biol Crystallogr. 2004 Jun;60(Pt 6):1173-6. Epub 2004, May 21. PMID:15159592
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