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1g9h

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1g9h, resolution 1.80Å ()
Ligands: , , , ,
Activity: Alpha-amylase, with EC number 3.2.1.1
Related: 1aqh, 1aqm, 1b0i, 1g94
Resources: FirstGlance, OCA, PDBsum, RCSB
Coordinates: save as pdb, mmCIF, xml



Contents

TERNARY COMPLEX BETWEEN PSYCHROPHILIC ALPHA-AMYLASE, COMII (PSEUDO TRI-SACCHARIDE FROM BAYER) AND TRIS (2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL)

Publication Abstract from PubMed

The psychrophilic Pseudoalteromonas haloplanctis alpha-amylase is shown to form ternary complexes with two alpha-amylase inhibitors present in the active site region, namely, a molecule of Tris and a trisaccharide inhibitor or heptasaccharide inhibitor, respectively. The crystal structures of these complexes have been determined by X-ray crystallography to 1.80 and 1.74 A resolution, respectively. In both cases, the prebound inhibitor Tris is expelled from the active site by the incoming oligosaccharide inhibitor substrate analogue, but stays linked to it, forming well-defined ternary complexes with the enzyme. These results illustrate competition in the crystalline state between two inhibitors, an oligosaccharide substrate analogue and a Tris molecule, bound at the same time in the active site region. Taken together, these structures show that the enzyme performs transglycosylation in the complex with the pseudotetrasaccharide acarbose (confirmed by a mutant structure), leading to a well-defined heptasaccharide, considered as a more potent inhibitor. Furthermore, the substrate-induced ordering of water molecules within a channel highlights a possible pathway used for hydrolysis of starch and related poly- and oligosaccharides.

Crystallographic evidence of a transglycosylation reaction: ternary complexes of a psychrophilic alpha-amylase., Aghajari N, Roth M, Haser R, Biochemistry. 2002 Apr 2;41(13):4273-80. PMID:11914073

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

About this Structure

1g9h is a 1 chain structure with sequence from Pseudoalteromonas haloplanktis. Full crystallographic information is available from OCA.

See Also

Reference

  • Aghajari N, Roth M, Haser R. Crystallographic evidence of a transglycosylation reaction: ternary complexes of a psychrophilic alpha-amylase. Biochemistry. 2002 Apr 2;41(13):4273-80. PMID:11914073

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