1itc
From Proteopedia
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|PDB= 1itc |SIZE=350|CAPTION= <scene name='initialview01'>1itc</scene>, resolution 2.10Å | |PDB= 1itc |SIZE=350|CAPTION= <scene name='initialview01'>1itc</scene>, resolution 2.10Å | ||
|SITE= | |SITE= | ||
| - | |LIGAND= <scene name='pdbligand= | + | |LIGAND= <scene name='pdbligand=ACY:ACETIC+ACID'>ACY</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=GLC:GLUCOSE'>GLC</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene> |
| - | |ACTIVITY= [http://en.wikipedia.org/wiki/Beta-amylase Beta-amylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.2 3.2.1.2] | + | |ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/Beta-amylase Beta-amylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.2 3.2.1.2] </span> |
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY=[[5bca|5BCA]], [[1itd|1ITD]], [[1itj|1ITJ]] | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1itc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1itc OCA], [http://www.ebi.ac.uk/pdbsum/1itc PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1itc RCSB]</span> | ||
}} | }} | ||
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[[Category: Nishimura, S.]] | [[Category: Nishimura, S.]] | ||
[[Category: Nitta, Y.]] | [[Category: Nitta, Y.]] | ||
| - | [[Category: ACY]] | ||
| - | [[Category: CA]] | ||
| - | [[Category: GLC]] | ||
| - | [[Category: SO4]] | ||
[[Category: beta-amylase]] | [[Category: beta-amylase]] | ||
[[Category: catalytic-site mutant]] | [[Category: catalytic-site mutant]] | ||
| Line 39: | Line 38: | ||
[[Category: raw-starch binding domain]] | [[Category: raw-starch binding domain]] | ||
| - | ''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 21:24:23 2008'' |
Revision as of 18:24, 30 March 2008
| |||||||
| , resolution 2.10Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , , , | ||||||
| Activity: | Beta-amylase, with EC number 3.2.1.2 | ||||||
| Related: | 5BCA, 1ITD, 1ITJ
| ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Beta-Amylase from Bacillus cereus var. mycoides Complexed with Maltopentaose
Overview
The X-ray crystal structure of a catalytic site mutant of beta-amylase, E172A (Glu172 --> Ala), from Bacillus cereus var. mycoides complexed with a substrate, maltopentaose (G5), and the wild-type enzyme complexed with maltose were determined at 2.1 and 2.0 A resolution, respectively. Clear and continuous density corresponding to G5 was observed in the active site of E172A, and thus, the substrate, G5, was not hydrolyzed. All glucose residues adopted a relaxed (4)C(1) conformation, and the conformation of the maltose unit for Glc2 and Glc3 was much different from those of other maltose units, where each glucose residue of G5 is named Glc1-Glc5 (Glc1 is at the nonreducing end). A water molecule was observed 3.3 A from the C1 atom of Glc2, and 3.0 A apart from the OE1 atom of Glu367 which acts as a general base. In the wild-type enzyme-maltose complex, two maltose molecules bind at subsites -2 and -1 and at subsites +1 and +2 in tandem. The conformation of the maltose molecules was similar to that of the condensation product of soybean beta-amylase, but differed from that of G5 in E172A. When the substrate flips between Glc2 and Glc3, the conformational energy of the maltose unit was calculated to be 20 kcal/mol higher than that of the cis conformation by MM3. We suggest that beta-amylase destabilizes the bond that is to be broken in the ES complex, decreasing the activation energy, DeltaG(++), which is the difference in free energy between this state and the transition state.
About this Structure
1ITC is a Single protein structure of sequence from Bacillus cereus. Full crystallographic information is available from OCA.
Reference
Crystal structure of a catalytic site mutant of beta-amylase from Bacillus cereus var. mycoides cocrystallized with maltopentaose., Miyake H, Kurisu G, Kusunoki M, Nishimura S, Kitamura S, Nitta Y, Biochemistry. 2003 May 20;42(19):5574-81. PMID:12741813
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