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1xh1

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Current revision

Structure of the N298S variant of human pancreatic alpha-amylase complexed with chloride

Structural highlights

1xh1 is a 1 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 2.03Å
Ligands:	, , ,
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

AMYP_HUMAN

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

The mechanism of allosteric activation of alpha-amylase by chloride has been studied through structural and kinetic experiments focusing on the chloride-dependent N298S variant of human pancreatic alpha-amylase (HPA) and a chloride-independent TAKA-amylase. Kinetic analysis of the HPA variant clearly demonstrates the pronounced activating effect of chloride ion binding on reaction rates and its effect on the pH-dependence of catalysis. Structural alterations observed in the N298S variant upon chloride ion binding suggest that the chloride ion plays a variety of roles that serve to promote catalysis. One of these is having a strong influence on the positioning of the acid/base catalyst residue E233. Absence of chloride ion results in multiple conformations for this residue and unexpected enzymatic products. Chloride ion and N298 also appear to stabilize a helical region of polypeptide chain from which projects the flexible substrate binding loop unique to chloride-dependent alpha-amylases. This structural feature also serves to properly orient the catalytically essential residue D300. Comparative analyses show that the chloride-independent alpha-amylases compensate for the absence of bound chloride by substituting a hydrophobic core, altering the manner in which substrate interactions are made and shifting the placement of N298. These evolutionary differences presumably arise in response to alternative operating environments or the advantage gained in a particular product profile. Attempts to engineer chloride-dependence into the chloride-independent TAKA-amylase point out the complexity of this system, and the fact that a multitude of factors play a role in binding chloride ion in the chloride-dependent alpha-amylases.

Structural and mechanistic studies of chloride induced activation of human pancreatic alpha-amylase.,Maurus R, Begum A, Kuo HH, Racaza A, Numao S, Andersen C, Tams JW, Vind J, Overall CM, Withers SG, Brayer GD Protein Sci. 2005 Mar;14(3):743-55. PMID:15722449^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Maurus R, Begum A, Kuo HH, Racaza A, Numao S, Andersen C, Tams JW, Vind J, Overall CM, Withers SG, Brayer GD. Structural and mechanistic studies of chloride induced activation of human pancreatic alpha-amylase. Protein Sci. 2005 Mar;14(3):743-55. PMID:15722449 doi:14/3/743

1 Structural highlights
2 Function
3 Evolutionary Conservation
4 Publication Abstract from PubMed
5 See Also
6 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/1xh1"

@@ Line 3: / Line 3: @@
 <StructureSection load='1xh1' size='340' side='right'caption='[[1xh1]], [[Resolution|resolution]] 2.03&Aring;' scene=''>
 == Structural highlights ==
-<table><tr><td colspan='2'>[[1xh1]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XH1 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1XH1 FirstGlance]. <br>
+<table><tr><td colspan='2'>[[1xh1]] is a 1 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=1XH1 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1XH1 FirstGlance]. <br>
-</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=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene></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]] 2.03&#8491;</td></tr>
-<tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=PCA:PYROGLUTAMIC+ACID'>PCA</scene></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=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=PCA:PYROGLUTAMIC+ACID'>PCA</scene></td></tr>
-<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[1xgz|1xgz]], [[1xh0|1xh0]], [[1xh2|1xh2]]</div></td></tr>
-<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/Alpha-amylase Alpha-amylase], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.1 3.2.1.1] </span></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=1xh1 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1xh1 OCA], [https://pdbe.org/1xh1 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1xh1 RCSB], [https://www.ebi.ac.uk/pdbsum/1xh1 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1xh1 ProSAT]</span></td></tr>
 </table>
+== Function ==
+[https://www.uniprot.org/uniprot/AMYP_HUMAN AMYP_HUMAN]
 == Evolutionary Conservation ==
 [[Image:Consurf_key_small.gif|200px|right]]
@@ Line 36: / Line 36: @@
 __TOC__
 </StructureSection>
-[[Category: Alpha-amylase]]
+[[Category: Homo sapiens]]
-[[Category: Human]]
 [[Category: Large Structures]]
-[[Category: Begum, A]]
+[[Category: Begum A]]
-[[Category: Brayer, G D]]
+[[Category: Brayer GD]]
-[[Category: Kuo, H H]]
+[[Category: Kuo HH]]
-[[Category: Maurus, R]]
+[[Category: Maurus R]]
-[[Category: Numao, S]]
+[[Category: Numao S]]
-[[Category: Overall, C M]]
+[[Category: Overall CM]]
-[[Category: Racaza, A]]
+[[Category: Racaza A]]
-[[Category: Withers, S G]]
+[[Category: Withers SG]]
-[[Category: Acarbose]]
-[[Category: Amylase]]
-[[Category: Chloride]]
-[[Category: Enzyme]]
-[[Category: Hydrolase]]
-[[Category: Inhibitor]]

1xh1

From Proteopedia

Current revision

Structure of the N298S variant of human pancreatic alpha-amylase complexed with chloride

Structural highlights

Function

Evolutionary Conservation

Publication Abstract from PubMed

See Also

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

Views

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