1smd: Difference between revisions
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==HUMAN SALIVARY AMYLASE== | |||
<StructureSection load='1smd' size='340' side='right'caption='[[1smd]], [[Resolution|resolution]] 1.60Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[1smd]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. The February 2006 RCSB PDB [https://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/index.html Molecule of the Month] feature on ''Alpha-amylase'' by David S. Goodsell is [https://dx.doi.org/10.2210/rcsb_pdb/mom_2006_2 10.2210/rcsb_pdb/mom_2006_2]. The June 2011 RCSB PDB [https://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/index.html Molecule of the Month] feature on ''Glucansucrase'' by David Goodsell is [https://dx.doi.org/10.2210/rcsb_pdb/mom_2011_6 10.2210/rcsb_pdb/mom_2011_6]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1SMD OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1SMD 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]] 1.6Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=PCA:PYROGLUTAMIC+ACID'>PCA</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=1smd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1smd OCA], [https://pdbe.org/1smd PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1smd RCSB], [https://www.ebi.ac.uk/pdbsum/1smd PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1smd ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/AMY1A_HUMAN AMY1A_HUMAN] Calcium-binding enzyme that initiates starch digestion in the oral cavity (PubMed:12527308). Catalyzes the hydrolysis of internal (1->4)-alpha-D-glucosidic bonds, yielding a mixture of maltose, isomaltose, small amounts of glucose as well as small linear and branched oligosaccharides called dextrins (PubMed:12527308).<ref>PMID:12527308</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/sm/1smd_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=1smd ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Salivary alpha-amylase, a major component of human saliva, plays a role in the initial digestion of starch and may be involved in the colonization of bacteria involved in early dental plaque formation. The three-dimensional atomic structure of salivary amylase has been determined to understand the structure-function relationships of this enzyme. This structure was refined to an R value of 18.4% with 496 amino-acid residues, one calcium ion, one chloride ion and 170 water molecules. Salivary amylase folds into a multidomain structure consisting of three domains, A, B and C. Domain A has a (beta/alpha)(8-) barrel structure, domain B has no definite topology and domain C has a Greek-key barrel structure. The Ca(2+) ion is bound to Asnl00, Arg158, Asp167, His201 and three water molecules. The Cl(-) ion is bound to Arg195, Asn298 and Arg337 and one water molecule. The highly mobile glycine-rich loop 304-310 may act as a gateway for substrate binding and be involved in a 'trap-release' mechanism in the hydrolysis of substrates. Strategic placement of calcium and chloride ions, as well as histidine and tryptophan residues may play a role in differentiating between the glycone and aglycone ends of the polysaccharide substrates. Salivary amylase also possesses a suitable site for binding to enamel surfaces and provides potential sites for the binding of bacterial adhesins. | |||
Structure of human salivary alpha-amylase at 1.6 A resolution: implications for its role in the oral cavity.,Ramasubbu N, Paloth V, Luo Y, Brayer GD, Levine MJ Acta Crystallogr D Biol Crystallogr. 1996 May 1;52(Pt 3):435-46. PMID:15299664<ref>PMID:15299664</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 1smd" style="background-color:#fffaf0;"></div> | |||
== | ==See Also== | ||
*[[Amylase 3D structures|Amylase 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Alpha-amylase]] | [[Category: Alpha-amylase]] | ||
[[Category: Glucansucrase]] | |||
[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
[[Category: | [[Category: Large Structures]] | ||
[[Category: | [[Category: RCSB PDB Molecule of the Month]] | ||
[[Category: | [[Category: Ramasubbu N]] | ||
