1e3x: Difference between revisions
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|PDB= 1e3x |SIZE=350|CAPTION= <scene name='initialview01'>1e3x</scene>, resolution 1.9Å | |PDB= 1e3x |SIZE=350|CAPTION= <scene name='initialview01'>1e3x</scene>, resolution 1.9Å | ||
|SITE= <scene name='pdbsite=ACT:Active+Site+Residues'>ACT</scene> | |SITE= <scene name='pdbsite=ACT:Active+Site+Residues'>ACT</scene> | ||
|LIGAND= <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene> | |LIGAND= <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene> | ||
|ACTIVITY= [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] | |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> | ||
|GENE= | |GENE= | ||
|DOMAIN= | |||
|RELATEDENTRY= | |||
|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1e3x FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1e3x OCA], [http://www.ebi.ac.uk/pdbsum/1e3x PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1e3x RCSB]</span> | |||
}} | }} | ||
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[[Category: Turkenburg, J P.]] | [[Category: Turkenburg, J P.]] | ||
[[Category: Wilson, K S.]] | [[Category: Wilson, K S.]] | ||
[[Category: amylase]] | [[Category: amylase]] | ||
[[Category: family 13]] | [[Category: family 13]] | ||
[[Category: hydrolase]] | [[Category: hydrolase]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 19:54:34 2008'' | ||
Revision as of 19:54, 30 March 2008
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| , resolution 1.9Å | |||||||
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| Sites: | |||||||
| Ligands: | , | ||||||
| Activity: | Alpha-amylase, with EC number 3.2.1.1 | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
NATIVE STRUCTURE OF CHIMAERIC AMYLASE FROM B. AMYLOLIQUEFACIENS AND B. LICHENIFORMIS AT 1.92A
OverviewOverview
Several chimeric alpha-amylases genes were constructed by an in vivo recombination technique from the Bacillus amyloliquefaciens and Bacillus licheniformis genes. One of the fusion amylases (hereafter BA2), consisting of residues 1-300 from B. amyloliquefaciens and 301-483 from B. licheniformis, has been extensively studied by X-ray crystallography at resolutions between 2.2 and 1.7 A. The 3-dimensional structure of the native enzyme was solved by multiple isomorphous replacement, and refined at a resolution of 1.7 A. It consists of 483 amino acids, organized similarly to the known B. lichiniformis alpha-amylase structure [Machius et al. (1995) J. Mol. Biol. 246, 545-559], but features 4 bound calcium ions. Two of these form part of a linear cluster of three ions, the central ion being attributed to sodium. This cluster lies at the junction of the A and B domains with one calcium of the cluster structurally equivalent to the major Ca(2+) binding site of fungal alpha-amylases. The third calcium ion is found at the interface of the A and C domains. BA2 contains a fourth calcium site, not observed in the B. licheniformis alpha-amylase structure. It is found on the C domain where it bridges the two beta-sheets. Three acid residues (Glu261, Asp328, and Asp231) form an active site similar to that seen in other amylases. In the presence of TRIS buffer, a single molecule of TRIS occupies the -1 subsite of the enzyme where it is coordinated by the three active-center carboxylates. Kinetic data reveal that BA2 displays properties intermediate to those of its parents. Data for crystals soaked in maltooligosaccharides reveal the presence of a maltotriose binding site on the N-terminal face of the (beta/alpha)(8) barrel of the molecule, not previously described for any alpha-amylase structure, the biological function of which is unclear. Data for a complex soaked with the tetrasaccharide inhibitor acarbose, at 1.9 A, reveal a decasaccharide moiety, spanning the -7 to +3 subsites of the enzyme. The unambiguous presence of three unsaturated rings in the (2)H(3) half-chair/(2)E envelope conformation, adjacent to three 6-deoxypyranose units, clearly demonstrates synthesis of this acarbose-derived decasaccharide by a two-step transglycosylation mechanism.
About this StructureAbout this Structure
1E3X is a Single protein structure of sequence from Bacillus amyloliquefaciens. Full crystallographic information is available from OCA.
ReferenceReference
Structural analysis of a chimeric bacterial alpha-amylase. High-resolution analysis of native and ligand complexes., Brzozowski AM, Lawson DM, Turkenburg JP, Bisgaard-Frantzen H, Svendsen A, Borchert TV, Dauter Z, Wilson KS, Davies GJ, Biochemistry. 2000 Aug 8;39(31):9099-107. PMID:10924103
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