1t3m
Structure of the isoaspartyl peptidase with L-asparaginase activity from E. coliStructure of the isoaspartyl peptidase with L-asparaginase activity from E. coli
Structural highlights
FunctionIAAA_ECOLI Degrades proteins damaged by L-isoaspartyl residue formation (also known as beta-Asp residues). Degrades L-isoaspartyl-containing di- and maybe also tripeptides. Also has L-asparaginase activity, although this may not be its principal function.[1] May be involved in glutathione, and possibly other peptide, transport, although these results could also be due to polar effects of disruption.[2] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe 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. 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[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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