View source for 3lpo


==Crystal structure of the N-terminal domain of sucrase-isomaltase==
<StructureSection load='3lpo' size='340' side='right'caption='[[3lpo]], [[Resolution|resolution]] 3.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3lpo]] is a 4 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=3LPO OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3LPO 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]] 3.2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BMA:BETA-D-MANNOSE'>BMA</scene>, <scene name='pdbligand=MAN:ALPHA-D-MANNOSE'>MAN</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</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=3lpo FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3lpo OCA], [https://pdbe.org/3lpo PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3lpo RCSB], [https://www.ebi.ac.uk/pdbsum/3lpo PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3lpo ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/SUIS_HUMAN SUIS_HUMAN] Congenital sucrase-isomaltase deficiency. Defects in SI are the cause of congenital sucrase-isomaltase deficiency (CSID) [MIM:[https://omim.org/entry/222900 222900]; also known as disaccharide intolerance I. CSID is an autosomal recessive intestinal disorder that is clinically characterized by fermentative diarrhea, abdominal pain, and cramps upon ingestion of sugar. The symptoms are the consequence of absent or drastically reduced enzymatic activities of sucrase and isomaltase. The prevalence of CSID is 0.02 % in individuals of European descent and appears to be much higher in Greenland, Alaskan, and Canadian native people. CSID arises due to post-translational perturbations in the intracellular transport, polarized sorting, aberrant processing, and defective function of SI.<ref>PMID:8609217</ref> <ref>PMID:10903344</ref> <ref>PMID:11340066</ref> <ref>PMID:14724820</ref> <ref>PMID:16329100</ref> 
== Function ==
[https://www.uniprot.org/uniprot/SUIS_HUMAN SUIS_HUMAN] Plays an important role in the final stage of carbohydrate digestion. Isomaltase activity is specific for both alpha-1,4- and alpha-1,6-oligosaccharides.<ref>PMID:20356844</ref> 
== 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/lp/3lpo_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=3lpo ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Human maltase-glucoamylase (MGAM) and sucrase-isomaltase (SI) are small intestinal enzymes that work concurrently to hydrolyze the mixture of linear alpha-1,4- and branched alpha-1,6-oligosaccharide substrates that typically make up terminal starch digestion products. MGAM and SI are each composed of duplicated catalytic domains, N- and C-terminal, which display overlapping substrate specificities. The N-terminal catalytic domain of human MGAM (ntMGAM) has a preference for short linear alpha-1,4-oligosaccharides, whereas N-terminal SI (ntSI) has a broader specificity for both alpha-1,4- and alpha-1,6-oligosaccharides. Here we present the crystal structure of the human ntSI, in apo form to 3.2 A and in complex with the inhibitor kotalanol to 2.15 A resolution. Structural comparison with the previously solved structure of ntMGAM reveals key active site differences in ntSI, including a narrow hydrophobic +1 subsite, which may account for its additional substrate specificity for alpha-1,6 substrates.

Structural basis for substrate selectivity in human maltase-glucoamylase and sucrase-isomaltase N-terminal domains.,Sim L, Willemsma C, Mohan S, Naim HY, Pinto BM, Rose DR J Biol Chem. 2010 Jun 4;285(23):17763-70. Epub 2010 Mar 31. PMID:20356844<ref>PMID:20356844</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 3lpo" style="background-color:#fffaf0;"></div>

==See Also==
*[[Alpha-glucosidase 3D structures|Alpha-glucosidase 3D structures]]
*[[Sucrase-isomaltase|Sucrase-isomaltase]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Rose DR]]
[[Category: Sim L]]