View source for 4gn9


==mouse SMP30/GNL-glucose complex==
<StructureSection load='4gn9' size='340' side='right'caption='[[4gn9]], [[Resolution|resolution]] 2.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4gn9]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4GN9 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4GN9 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BGC:BETA-D-GLUCOSE'>BGC</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=4gn9 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4gn9 OCA], [https://pdbe.org/4gn9 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4gn9 RCSB], [https://www.ebi.ac.uk/pdbsum/4gn9 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4gn9 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/RGN_MOUSE RGN_MOUSE] Gluconolactonase with low activity towards other sugar lactones, including gulonolactone and galactonolactone. Catalyzes a key step in ascorbic acid (vitamin C) biosynthesis. Can also hydrolyze diisopropyl phosphorofluoridate and phenylacetate (in vitro). Calcium-binding protein. Modulates Ca(2+) signaling, and Ca(2+)-dependent cellular processes and enzyme activities (By similarity).<ref>PMID:16585534</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The senescence marker protein-30 (SMP30), which is also called regucalcin, exhibits gluconolactonase (GNL) activity. Biochemical and biological analyses revealed that SMP30/GNL catalyzes formation of the gamma-lactone-ring of L-gulonate in the ascorbic acid biosynthesis pathway. The molecular basis of the gamma-lactone formation, however, remains elusive due to the lack of structural information on SMP30/GNL in complex with its substrate. Here, we report the crystal structures of mouse SMP30/GNL and its complex with xylitol, a substrate analogue, and those with 1,5-anhydro-D-glucitol and D-glucose, product analogues. Comparison of the crystal structure of mouse SMP30/GNL with other related enzymes has revealed unique characteristics of mouse SMP30/GNL. First, the substrate-binding pocket of mouse SMP30/GNL is designed to specifically recognize monosaccharide molecules. The divalent metal ion in the active site and polar residues lining the substrate-binding cavity interact with hydroxyl groups of substrate/product analogues. Second, in mouse SMP30/GNL, a lid loop covering the substrate-binding cavity seems to hamper the binding of L-gulonate in an extended (or all-trans) conformation; L-gulonate seems to bind to the active site in a folded conformation. In contrast, the substrate-binding cavities of the other related enzymes are open to the solvent and do not have a cover. This structural feature of mouse SMP30/GNL seems to facilitate the gamma-lactone-ring formation.

Structural basis of the gamma-lactone-ring formation in ascorbic acid biosynthesis by the senescence marker protein-30/gluconolactonase.,Aizawa S, Senda M, Harada A, Maruyama N, Ishida T, Aigaki T, Ishigami A, Senda T PLoS One. 2013;8(1):e53706. doi: 10.1371/journal.pone.0053706. Epub 2013 Jan 22. PMID:23349732<ref>PMID:23349732</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4gn9" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Mus musculus]]
[[Category: Aigaki T]]
[[Category: Aizawa S]]
[[Category: Harada A]]
[[Category: Ishida T]]
[[Category: Ishigami A]]
[[Category: Maruyama N]]
[[Category: Senda M]]
[[Category: Senda T]]