1smd: Difference between revisions

Revision as of 08:53, 3 May 2008

HUMAN SALIVARY AMYLASE

OverviewOverview

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.

About this StructureAbout this Structure

1SMD is a Single protein structure of sequence from Homo sapiens. The following page contains interesting information on the relation of 1SMD with [Alpha-amylase]. Full crystallographic information is available from OCA.

ReferenceReference

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 Page seeded by OCA on Sat May 3 08:53:01 2008

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA

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 [[Image:1smd.gif|left|200px]]
- {{Structure
+<!--
-|PDB= 1smd |SIZE=350|CAPTION= <scene name='initialview01'>1smd</scene>, resolution 1.6&Aring;
+The line below this paragraph, containing "STRUCTURE_1smd", creates the "Structure Box" on the page.
-|SITE=
+You may change the PDB parameter (which sets the PDB file loaded into the applet)
-|LIGAND= <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=PCA:PYROGLUTAMIC+ACID'>PCA</scene>
+or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
-|ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/Alpha-amylase Alpha-amylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.1 3.2.1.1] </span>
+or leave the SCENE parameter empty for the default display.
-|GENE=
+-->
-|DOMAIN=
+{{STRUCTURE_1smd|  PDB=1smd  |  SCENE=  }}
-|RELATEDENTRY=
-|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1smd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1smd OCA], [http://www.ebi.ac.uk/pdbsum/1smd PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1smd RCSB]</span>
-}}
 '''HUMAN SALIVARY AMYLASE'''
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 [[Category: Single protein]]
 [[Category: Ramasubbu, N.]]
-[[Category: carbohydrate metabolism]]
+[[Category: Carbohydrate metabolism]]
-[[Category: hydrolase]]
+[[Category: Hydrolase]]
-[[Category: o-glycosyl]]
+[[Category: O-glycosyl]]
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May  3 08:53:01 2008''
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 23:44:01 2008''