View source for 1hny


==The structure of human pancreatic alpha-amylase at 1.8 angstroms resolution and comparisons with related enzymes==
<StructureSection load='1hny' size='340' side='right'caption='[[1hny]], [[Resolution|resolution]] 1.80&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1hny]] 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]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1HNY OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1HNY 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]] 1.8&#8491;</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=1hny FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1hny OCA], [https://pdbe.org/1hny PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1hny RCSB], [https://www.ebi.ac.uk/pdbsum/1hny PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1hny ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/AMYP_HUMAN AMYP_HUMAN] 
== 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/hn/1hny_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=1hny ConSurf].
<div style="clear:both"></div>
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== Publication Abstract from PubMed ==
The structure of human pancreatic alpha-amylase has been determined to 1.8 A resolution using X-ray diffraction techniques. This enzyme is found to be composed of three structural domains. The largest is Domain A (residues 1-99, 169-404), which forms a central eight-stranded parallel beta-barrel, to one end of which are located the active site residues Asp 197, Glu 233, and Asp 300. Also found in this vicinity is a bound chloride ion that forms ligand interactions to Arg 195, Asn 298, and Arg 337. Domain B is the smallest (residues 100-168) and serves to form a calcium binding site against the wall of the beta-barrel of Domain A. Protein groups making ligand interactions to this calcium include Asn 100, Arg 158, Asp 167, and His 201. Domain C (residues 405-496) is made up of anti-parallel beta-structure and is only loosely associated with Domains A and B. It is notable that the N-terminal glutamine residue of human pancreatic alpha-amylase undergoes a posttranslational modification to form a stable pyrrolidone derivative that may provide protection against other digestive enzymes. Structure-based comparisons of human pancreatic alpha-amylase with functionally related enzymes serve to emphasize three points. Firstly, despite this approach facilitating primary sequence alignments with respect to the numerous insertions and deletions present, overall there is only approximately 15% sequence homology between the mammalian and fungal alpha-amylases. Secondly, in contrast, these same studies indicate that significant structural homology is present and of the order of approximately 70%. Thirdly, the positioning of Domain C can vary considerably between alpha-amylases. In terms of the more closely related porcine enzyme, there are four regions of polypeptide chain (residues 237-250, 304-310, 346-354, and 458-461) with significantly different conformations from those in human pancreatic alpha-amylase. At least two of these could play a role in observed differential substrate and cleavage pattern specificities between these enzymes. Similarly, amino acid differences between human pancreatic and salivary alpha-amylases have been localized and a number of these occur in the vicinity of the active site.

The structure of human pancreatic alpha-amylase at 1.8 A resolution and comparisons with related enzymes.,Brayer GD, Luo Y, Withers SG Protein Sci. 1995 Sep;4(9):1730-42. PMID:8528071<ref>PMID:8528071</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 1hny" style="background-color:#fffaf0;"></div>

==See Also==
*[[Amylase 3D structures|Amylase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Alpha-amylase]]
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: RCSB PDB Molecule of the Month]]
[[Category: Brayer GD]]
[[Category: Luo Y]]