1t3m
From Proteopedia
(New page: 200px<br /><applet load="1t3m" size="450" color="white" frame="true" align="right" spinBox="true" caption="1t3m, resolution 1.65Å" /> '''Structure of the iso...) |
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| - | [[Image:1t3m.jpg|left|200px]]<br /><applet load="1t3m" size=" | + | [[Image:1t3m.jpg|left|200px]]<br /><applet load="1t3m" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1t3m, resolution 1.65Å" /> | caption="1t3m, resolution 1.65Å" /> | ||
'''Structure of the isoaspartyl peptidase with L-asparaginase activity from E. coli'''<br /> | '''Structure of the isoaspartyl peptidase with L-asparaginase activity from E. coli'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The crystal structure of the Escherichia coli enzyme (EcAIII) with | + | 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 Structure== | ==About this Structure== | ||
| - | 1T3M is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with NA and NO3 as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Asparaginase Asparaginase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.5.1.1 3.5.1.1] Full crystallographic information is available from [http:// | + | 1T3M is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=NA:'>NA</scene> and <scene name='pdbligand=NO3:'>NO3</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Asparaginase Asparaginase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.5.1.1 3.5.1.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1T3M OCA]. |
==Reference== | ==Reference== | ||
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[[Category: type iii l-asparaginase]] | [[Category: type iii l-asparaginase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:09:31 2008'' |
Revision as of 13:09, 21 February 2008
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Structure of the isoaspartyl peptidase with L-asparaginase activity from E. coli
Overview
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 Structure
1T3M is a Protein complex structure of sequences from Escherichia coli with and as ligands. Active as Asparaginase, with EC number 3.5.1.1 Full crystallographic information is available from OCA.
Reference
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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