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| - | [[Image:1lwj.jpg|left|200px]] | |
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| - | {{Structure
| + | ==CRYSTAL STRUCTURE OF T. MARITIMA 4-ALPHA-GLUCANOTRANSFERASE/ACARBOSE COMPLEX== |
| - | |PDB= 1lwj |SIZE=350|CAPTION= <scene name='initialview01'>1lwj</scene>, resolution 2.50Å
| + | <StructureSection load='1lwj' size='340' side='right'caption='[[1lwj]], [[Resolution|resolution]] 2.50Å' scene=''> |
| - | |SITE=
| + | == Structural highlights == |
| - | |LIGAND= <scene name='pdbligand=ACG:MODIFIED+ACARBOSE+PENTASACCHARIDE'>ACG</scene> and <scene name='pdbligand=CA:CALCIUM ION'>CA</scene> | + | <table><tr><td colspan='2'>[[1lwj]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Thermotoga_maritima Thermotoga maritima]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1LWJ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1LWJ FirstGlance]. <br> |
| - | |ACTIVITY= [http://en.wikipedia.org/wiki/4-alpha-glucanotransferase 4-alpha-glucanotransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.4.1.25 2.4.1.25]
| + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.5Å</td></tr> |
| - | |GENE= mgt ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=2336 Thermotoga maritima]) | + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACG:MODIFIED+ACARBOSE+PENTASACCHARIDE'>ACG</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</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=1lwj FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1lwj OCA], [https://pdbe.org/1lwj PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1lwj RCSB], [https://www.ebi.ac.uk/pdbsum/1lwj PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1lwj ProSAT]</span></td></tr> |
| | + | </table> |
| | + | == Function == |
| | + | [https://www.uniprot.org/uniprot/MGTA_THEMA MGTA_THEMA] |
| | + | == 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/lw/1lwj_consurf.spt"</scriptWhenChecked> |
| | + | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.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=1lwj ConSurf]. |
| | + | <div style="clear:both"></div> |
| | | | |
| - | '''CRYSTAL STRUCTURE OF T. MARITIMA 4-ALPHA-GLUCANOTRANSFERASE/ACARBOSE COMPLEX'''
| + | ==See Also== |
| - | | + | *[[Glycosyltransferase 3D structures|Glycosyltransferase 3D structures]] |
| - | | + | __TOC__ |
| - | ==Overview== | + | </StructureSection> |
| - | 4-alpha-Glucanotransferase (GTase) is an essential enzyme in alpha-1,4-glucan metabolism in bacteria and plants. It catalyses the transfer of maltooligosaccharides from an 1,4-alpha-D-glucan molecule to the 4-hydroxyl group of an acceptor sugar molecule. The crystal structures of Thermotoga maritima GTase and its complex with the inhibitor acarbose have been determined at 2.6A and 2.5A resolution, respectively. The GTase structure consists of three domains, an N-terminal domain with the (beta/alpha)(8) barrel topology (domain A), a 65 residue domain, domain B, inserted between strand beta3 and helix alpha6 of the barrel, and a C-terminal domain, domain C, which forms an antiparallel beta-structure. Analysis of the complex of GTase with acarbose has revealed the locations of five sugar-binding subsites (-2 to +3) in the active-site cleft lying between domain B and the C-terminal end of the (beta/alpha)(8) barrel. The structure of GTase closely resembles the family 13 glycoside hydrolases and conservation of key catalytic residues previously identified for this family is consistent with a double-displacement catalytic mechanism for this enzyme. A distinguishing feature of GTase is a pair of tryptophan residues, W131 and W218, which, upon the carbohydrate inhibitor binding, form a remarkable aromatic "clamp" that captures the sugar rings at the acceptor-binding sites +1 and +2. Analysis of the structure of the complex shows that sugar residues occupying subsites from -2 to +2 engage in extensive interactions with the protein, whereas the +3 glucosyl residue makes relatively few contacts with the enzyme. Thus, the structure suggests that four subsites, from -2 to +2, play the dominant role in enzyme-substrate recognition, consistent with the observation that the smallest donor for T.maritima GTase is maltotetraose, the smallest chain transferred is a maltosyl unit and that the smallest residual fragment after transfer is maltose. A close similarity between the structures of GTase and oligo-1,6-glucosidase has allowed the structural features that determine differences in substrate specificity of these two enzymes to be analysed.
| + | [[Category: Large Structures]] |
| - | | + | |
| - | ==About this Structure==
| + | |
| - | 1LWJ is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Thermotoga_maritima Thermotoga maritima]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1LWJ OCA].
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| - | | + | |
| - | ==Reference==
| + | |
| - | Crystal structure of Thermotoga maritima 4-alpha-glucanotransferase and its acarbose complex: implications for substrate specificity and catalysis., Roujeinikova A, Raasch C, Sedelnikova S, Liebl W, Rice DW, J Mol Biol. 2002 Aug 2;321(1):149-62. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/12139940 12139940]
| + | |
| - | [[Category: 4-alpha-glucanotransferase]]
| + | |
| - | [[Category: Single protein]] | + | |
| | [[Category: Thermotoga maritima]] | | [[Category: Thermotoga maritima]] |
| - | [[Category: Liebl, W.]] | + | [[Category: Liebl W]] |
| - | [[Category: Raasch, C.]] | + | [[Category: Raasch C]] |
| - | [[Category: Rice, D W.]] | + | [[Category: Rice DW]] |
| - | [[Category: Roujeinikova, A.]] | + | [[Category: Roujeinikova A]] |
| - | [[Category: Sedelnikova, S.]] | + | [[Category: Sedelnikova S]] |
| - | [[Category: ACG]]
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| - | [[Category: CA]]
| + | |
| - | [[Category: (beta/alpha)8 barrel]]
| + | |
| - | [[Category: acarbose]]
| + | |
| - | [[Category: alpha-amylase family]]
| + | |
| - | [[Category: thermotoga maritima]]
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| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 12:36:06 2008''
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