1hg1

<StructureSection load='1hg1' size='340' side='right' caption='[[1hg1]], [[Resolution|resolution]] 1.80&Aring;' scene=''>

<table><tr><td colspan='2'>[[1hg1]] is a 4 chain structure with sequence from [http://en.wikipedia.org/wiki/Erwinia_chrysanthemi Erwinia chrysanthemi]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1HG1 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1HG1 FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=DAS:D-ASPARTIC+ACID'>DAS</scene></td></tr>

<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1hfj|1hfj]], [[1hfk|1hfk]], [[1hfw|1hfw]], [[1hg0|1hg0]]</td></tr>

<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[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] </span></td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1hg1 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1hg1 OCA], [http://pdbe.org/1hg1 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1hg1 RCSB], [http://www.ebi.ac.uk/pdbsum/1hg1 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1hg1 ProSAT]</span></td></tr>

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== Publication Abstract from PubMed ==

Bacterial L-asparaginases, enzymes that catalyze the hydrolysis of L-asparagine to aspartic acid, have been used for over 30 years as therapeutic agents in the treatment of acute childhood lymphoblastic leukemia. Other substrates of asparaginases include L-glutamine, D-asparagine, and succinic acid monoamide. In this report, we present high-resolution crystal structures of the complexes of Erwinia chrysanthemi L-asparaginase (ErA) with the products of such reactions that also can serve as substrates, namely L-glutamic acid (L-Glu), D-aspartic acid (D-Asp), and succinic acid (Suc). Comparison of the four independent active sites within each complex indicates unique and specific binding of the ligand molecules; the mode of binding is also similar between complexes. The lack of the alpha-NH3(+) group in Suc, compared to L-Asp, does not affect the binding mode. The side chain of L-Glu, larger than that of L-Asp, causes several structural distortions in the ErA active side. The active site flexible loop (residues 15-33) does not exhibit stable conformation, resulting in suboptimal orientation of the nucleophile, Thr15. Additionally, the delta-COO(-) plane of L-Glu is approximately perpendicular to the plane of gamma-COO(-) in L-Asp bound to the asparaginase active site. Binding of D-Asp to the ErA active site is very distinctive compared to the other ligands, suggesting that the low activity of ErA against D-Asp could be mainly attributed to the low k(cat) value. A comparison of the amino acid sequence and the crystal structure of ErA with those of other bacterial L-asparaginases shows that the presence of two active-site residues, Glu63(ErA) and Ser254(ErA), may correlate with significant glutaminase activity, while their substitution by Gln and Asn, respectively, may lead to minimal L-glutaminase activity.

Structural basis for the activity and substrate specificity of Erwinia chrysanthemi L-asparaginase.,Aghaiypour K, Wlodawer A, Lubkowski J Biochemistry. 2001 May 15;40(19):5655-64. PMID:11341830<ref>PMID:11341830</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

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<div class="pdbe-citations 1hg1" style="background-color:#fffaf0;"></div>

*[[Asparaginase|Asparaginase]]

[[Category: Asparaginase]]

[[Category: Erwinia chrysanthemi]]

[[Category: Kolyani, K A]]

[[Category: Lubkowski, J]]

[[Category: Wlodawer, A]]

[[Category: Hydrolase]]