2qmj: Difference between revisions

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-[[Image:2qmj.jpg|left|200px]]
-<!--
-The line below this paragraph, containing "STRUCTURE_2qmj", creates the "Structure Box" on the page.
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-or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
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-{{STRUCTURE_2qmj|  PDB=2qmj  |  SCENE=  }}
-'''Crystral Structure of the N-terminal Subunit of Human Maltase-Glucoamylase in Complex with Acarbose'''
+==Crystral Structure of the N-terminal Subunit of Human Maltase-Glucoamylase in Complex with Acarbose==
+<StructureSection load='2qmj' size='340' side='right'caption='[[2qmj]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
+== Structural highlights ==
+<table><tr><td colspan='2'>[[2qmj]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2QMJ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2QMJ 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]] 1.9&#8491;</td></tr>
+<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=AC1:6-METHYL-5-(4,5,6-TRIHYDROXY-3-HYDROXYMETHYL-CYCLOHEX-2-ENYLAMINO)-TETRAHYDRO-PYRAN-2,3,4-TRIOL'>AC1</scene>, <scene name='pdbligand=GLC:ALPHA-D-GLUCOSE'>GLC</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=PRD_900007:alpha-acarbose'>PRD_900007</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=2qmj FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2qmj OCA], [https://pdbe.org/2qmj PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2qmj RCSB], [https://www.ebi.ac.uk/pdbsum/2qmj PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2qmj ProSAT]</span></td></tr>
+</table>
+== Function ==
+[https://www.uniprot.org/uniprot/MGA_HUMAN MGA_HUMAN] May serve as an alternate pathway for starch digestion when luminal alpha-amylase activity is reduced because of immaturity or malnutrition. May play a unique role in the digestion of malted dietary oligosaccharides used in food manufacturing.
+== Evolutionary Conservation ==
+[[Image:Consurf_key_small.gif|200px|right]]
+Check<jmol>
+  <jmolCheckbox>
+    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/qm/2qmj_consurf.spt"</scriptWhenChecked>
+    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked>
+    <text>to colour the structure by Evolutionary Conservation</text>
+  </jmolCheckbox>
+</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=2qmj ConSurf].
+<div style="clear:both"></div>
+<div style="background-color:#fffaf0;">
+== Publication Abstract from PubMed ==
+Human maltase-glucoamylase (MGAM) is one of the two enzymes responsible for catalyzing the last glucose-releasing step in starch digestion. MGAM is anchored to the small-intestinal brush-border epithelial cells and contains two homologous glycosyl hydrolase family 31 catalytic subunits: an N-terminal subunit (NtMGAM) found near the membrane-bound end and a C-terminal luminal subunit (CtMGAM). In this study, we report the crystal structure of the human NtMGAM subunit in its apo form (to 2.0 A) and in complex with acarbose (to 1.9 A). Structural analysis of the NtMGAM-acarbose complex reveals that acarbose is bound to the NtMGAM active site primarily through side-chain interactions with its acarvosine unit, and almost no interactions are made with its glycone rings. These observations, along with results from kinetic studies, suggest that the NtMGAM active site contains two primary sugar subsites and that NtMGAM and CtMGAM differ in their substrate specificities despite their structural relationship. Additional sequence analysis of the CtMGAM subunit suggests several features that could explain the higher affinity of the CtMGAM subunit for longer maltose oligosaccharides. The results provide a structural basis for the complementary roles of these glycosyl hydrolase family 31 subunits in the bioprocessing of complex starch structures into glucose.
-==Overview==
+Human intestinal maltase-glucoamylase: crystal structure of the N-terminal catalytic subunit and basis of inhibition and substrate specificity.,Sim L, Quezada-Calvillo R, Sterchi EE, Nichols BL, Rose DR J Mol Biol. 2008 Jan 18;375(3):782-92. Epub 2007 Nov 1. PMID:18036614<ref>PMID:18036614</ref>
-Human maltase-glucoamylase (MGAM) is one of the two enzymes responsible for catalyzing the last glucose-releasing step in starch digestion. MGAM is anchored to the small-intestinal brush-border epithelial cells and contains two homologous glycosyl hydrolase family 31 catalytic subunits: an N-terminal subunit (NtMGAM) found near the membrane-bound end and a C-terminal luminal subunit (CtMGAM). In this study, we report the crystal structure of the human NtMGAM subunit in its apo form (to 2.0 A) and in complex with acarbose (to 1.9 A). Structural analysis of the NtMGAM-acarbose complex reveals that acarbose is bound to the NtMGAM active site primarily through side-chain interactions with its acarvosine unit, and almost no interactions are made with its glycone rings. These observations, along with results from kinetic studies, suggest that the NtMGAM active site contains two primary sugar subsites and that NtMGAM and CtMGAM differ in their substrate specificities despite their structural relationship. Additional sequence analysis of the CtMGAM subunit suggests several features that could explain the higher affinity of the CtMGAM subunit for longer maltose oligosaccharides. The results provide a structural basis for the complementary roles of these glycosyl hydrolase family 31 subunits in the bioprocessing of complex starch structures into glucose.
-==About this Structure==
+From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
-QMJ is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2QMJ OCA].
+</div>
+<div class="pdbe-citations 2qmj" style="background-color:#fffaf0;"></div>
-==Reference==
+==See Also==
-Human intestinal maltase-glucoamylase: crystal structure of the N-terminal catalytic subunit and basis of inhibition and substrate specificity., Sim L, Quezada-Calvillo R, Sterchi EE, Nichols BL, Rose DR, J Mol Biol. 2008 Jan 18;375(3):782-92. Epub 2007 Nov 1. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/18036614 18036614]
+*[[Alpha-glucosidase 3D structures|Alpha-glucosidase 3D structures]]
+== References ==
+<references/>
+__TOC__
+</StructureSection>
 [[Category: Homo sapiens]]
-[[Category: Single protein]]
+[[Category: Large Structures]]
-[[Category: Rose, D R.]]
+[[Category: Rose DR]]
-[[Category: Sim, L.]]
+[[Category: Sim L]]
-[[Category: Glycoprotein]]
-[[Category: Glycosidase]]
-[[Category: Glycosyl hydrolase family 31]]
-[[Category: Hydrolase]]
-[[Category: Membrane]]
-[[Category: Multifunctional enzyme]]
-[[Category: Signal-anchor]]
-[[Category: Sulfation]]
-[[Category: Transmembrane]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May  4 15:12:43 2008''