PDBsum entry 1kxh

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Hydrolase PDB id
Protein chain
448 a.a. *
Waters ×205
* Residue conservation analysis

References listed in PDB file
Key reference
Title Crystallographic evidence of a transglycosylation reaction: ternary complexes of a psychrophilic alpha-Amylase.
Authors N.Aghajari, M.Roth, R.Haser.
Ref. Biochemistry, 2002, 41, 4273-4280. [DOI no: 10.1021/bi0160516]
PubMed id 11914073
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.
Secondary reference #1
Title Structures of the psychrophilic alteromonas haloplanctis alpha-Amylase give insights into cold adaptation at a molecular level.
Authors N.Aghajari, G.Feller, C.Gerday, R.Haser.
Ref. Structure, 1998, 6, 1503-1516. [DOI no: 10.1016/S0969-2126(98)00149-X]
PubMed id 9862804
Full text Abstract
Figure 4.
Figure 4. A representation of charges at the surfaces of (a) AHA, (b) HPA and (c) BLA, displayed at the same potential range. Color codes are: red, aspartic and glutamic acids; blue, lysines and arginines. This figure was generated with the program GRASP [57].
The above figure is reproduced from the cited reference with permission from Cell Press
Secondary reference #2
Title Crystal structures of the psychrophilic alpha-Amylase from alteromonas haloplanctis in its native form and complexed with an inhibitor.
Authors N.Aghajari, G.Feller, C.Gerday, R.Haser.
Ref. Protein Sci, 1998, 7, 564-572. [DOI no: 10.1002/pro.5560070304]
PubMed id 9541387
Full text Abstract
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