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1smd
From Proteopedia
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'''HUMAN SALIVARY AMYLASE''' | '''HUMAN SALIVARY AMYLASE''' | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Ramasubbu, N.]] | [[Category: Ramasubbu, N.]] | ||
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| - | [[Category: | + | [[Category: Hydrolase]] |
| - | [[Category: | + | [[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 | + | |
Revision as of 05:53, 3 May 2008
HUMAN SALIVARY AMYLASE
Overview
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 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.
Reference
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
