1smd

HUMAN SALIVARY AMYLASE

spinqualitylabelsall models 1smd, resolution 1.60Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1smd is a 1 chain structure with sequence from Homo sapiens. The February 2006 RCSB PDB Molecule of the Month feature on Alpha-amylase by David S. Goodsell is 10.2210/rcsb_pdb/mom_2006_2. The June 2011 RCSB PDB Molecule of the Month feature on Glucansucrase by David Goodsell is 10.2210/rcsb_pdb/mom_2011_6. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.6Å Ligands: CA, CL, PCA Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function 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). 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 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 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Amylase 3D structures

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