|
|
| (One intermediate revision not shown.) |
| Line 1: |
Line 1: |
| | | | |
| | ==Crystral Structure of the C-terminal Subunit of Human Maltase-Glucoamylase== | | ==Crystral Structure of the C-terminal Subunit of Human Maltase-Glucoamylase== |
| - | <StructureSection load='3ton' size='340' side='right' caption='[[3ton]], [[Resolution|resolution]] 2.95Å' scene=''> | + | <StructureSection load='3ton' size='340' side='right'caption='[[3ton]], [[Resolution|resolution]] 2.95Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[3ton]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3TON OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3TON FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[3ton]] is a 2 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=3TON OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3TON FirstGlance]. <br> |
| - | </td></tr><tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3top|3top]]</td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.953Å</td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">MGAM ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 HUMAN])</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=3ton FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3ton OCA], [https://pdbe.org/3ton PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3ton RCSB], [https://www.ebi.ac.uk/pdbsum/3ton PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3ton ProSAT]</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=3ton FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3ton OCA], [http://pdbe.org/3ton PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=3ton RCSB], [http://www.ebi.ac.uk/pdbsum/3ton PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=3ton ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://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. | + | [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. |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
| Line 19: |
Line 18: |
| | </div> | | </div> |
| | <div class="pdbe-citations 3ton" style="background-color:#fffaf0;"></div> | | <div class="pdbe-citations 3ton" style="background-color:#fffaf0;"></div> |
| | + | |
| | + | ==See Also== |
| | + | *[[Alpha-glucosidase 3D structures|Alpha-glucosidase 3D structures]] |
| | == References == | | == References == |
| | <references/> | | <references/> |
| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Human]] | + | [[Category: Homo sapiens]] |
| - | [[Category: Qin, X H]] | + | [[Category: Large Structures]] |
| - | [[Category: Ren, L M]] | + | [[Category: Qin XH]] |
| - | [[Category: Shen, Y]] | + | [[Category: Ren LM]] |
| - | [[Category: Carbohydrate/sugar binding]] | + | [[Category: Shen Y]] |
| - | [[Category: Hydrolase]]
| + | |
| - | [[Category: Membrane]]
| + | |
| Structural highlights
Function
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.
Publication Abstract from PubMed
Human maltase-glucoamylase (MGAM) hydrolyzes linear alpha-1,4-linked oligosaccharide substrates, playing a crucial role in the production of glucose in the human lumen and acting as an efficient drug target for type 2 diabetes and obesity. The amino- and carboxyl-terminal portions of MGAM (MGAM-N and MGAM-C) carry out the same catalytic reaction but have different substrate specificities. In this study, we report crystal structures of MGAM-C alone at a resolution of 3.1 A, and in complex with its inhibitor acarbose at a resolution of 2.9 A. Structural studies, combined with biochemical analysis, revealed that a segment of 21 amino acids in the active site of MGAM-C forms additional sugar subsites (+ 2 and + 3 subsites), accounting for the preference for longer substrates of MAGM-C compared with that of MGAM-N. Moreover, we discovered that a single mutation of Trp1251 to tyrosine in MGAM-C imparts a novel catalytic ability to digest branched alpha-1,6-linked oligosaccharides. These results provide important information for understanding the substrate specificity of alphaglucosidases during the process of terminal starch digestion, and for designing more efficient drugs to control type 2 diabetes or obesity.
Structural insight into substrate specificity of human intestinal maltase-glucoamylase.,Ren L, Qin X, Cao X, Wang L, Bai F, Bai G, Shen Y Protein Cell. 2011 Oct;2(10):827-36. Epub 2011 Nov 6. PMID:22058037[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Ren L, Qin X, Cao X, Wang L, Bai F, Bai G, Shen Y. Structural insight into substrate specificity of human intestinal maltase-glucoamylase. Protein Cell. 2011 Oct;2(10):827-36. Epub 2011 Nov 6. PMID:22058037 doi:10.1007/s13238-011-1105-3
|
