1j0h: Difference between revisions
New page: left|200px<br /><applet load="1j0h" size="450" color="white" frame="true" align="right" spinBox="true" caption="1j0h, resolution 1.90Å" /> '''Crystal structure of... |
No edit summary |
||
| Line 1: | Line 1: | ||
[[Image:1j0h.jpg|left|200px]]<br /><applet load="1j0h" size=" | [[Image:1j0h.jpg|left|200px]]<br /><applet load="1j0h" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1j0h, resolution 1.90Å" /> | caption="1j0h, resolution 1.90Å" /> | ||
'''Crystal structure of Bacillus stearothermophilus neopullulanase'''<br /> | '''Crystal structure of Bacillus stearothermophilus neopullulanase'''<br /> | ||
==Overview== | ==Overview== | ||
Crystal structures of Bacillus stearothermophilus TRS40 neopullulanase and | Crystal structures of Bacillus stearothermophilus TRS40 neopullulanase and its complexes with panose, maltotetraose and isopanose were determined at resolutions of 1.9, 2.4, 2.8 and 3.2A, respectively. Since the latter two carbohydrates are substrates of this enzyme, a deactivated mutant at the catalytic residue Glu357-->Gln was used for complex crystallization. The structures were refined at accuracies with r.m.s. deviations of bond lengths and bond angles ranging from 0.005A to 0.008A and 1.3 degrees to 1.4 degrees, respectively. The active enzyme forms a dimer in the crystalline state and in solution. The monomer enzyme is composed of four domains, N, A, B and C, and has a (beta/alpha)(8)-barrel in domain A. The active site lies between domain A and domain N from the other monomer. The results show that dimer formation makes the active-site cleft narrower than those of ordinary alpha-amylases, which may contribute to the unique substrate specificity of this enzyme toward both alpha-1,4 and alpha-1,6-glucosidic linkages. This specificity may be influenced by the subsite structure. Only subsites -1 and -2 are commonly occupied by the product and substrates, suggesting that equivocal recognition occurs at the other subsites, which contributes to the wide substrate specificity of this enzyme. | ||
==About this Structure== | ==About this Structure== | ||
1J0H is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Geobacillus_stearothermophilus Geobacillus stearothermophilus] with CL and CA as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Neopullulanase Neopullulanase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.135 3.2.1.135] Full crystallographic information is available from [http:// | 1J0H is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Geobacillus_stearothermophilus Geobacillus stearothermophilus] with <scene name='pdbligand=CL:'>CL</scene> and <scene name='pdbligand=CA:'>CA</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Neopullulanase Neopullulanase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.135 3.2.1.135] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1J0H OCA]. | ||
==Reference== | ==Reference== | ||
| Line 21: | Line 21: | ||
[[Category: beta-alpha-barrels]] | [[Category: beta-alpha-barrels]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:17:40 2008'' | ||
Revision as of 14:17, 21 February 2008
|
Crystal structure of Bacillus stearothermophilus neopullulanase
OverviewOverview
Crystal structures of Bacillus stearothermophilus TRS40 neopullulanase and its complexes with panose, maltotetraose and isopanose were determined at resolutions of 1.9, 2.4, 2.8 and 3.2A, respectively. Since the latter two carbohydrates are substrates of this enzyme, a deactivated mutant at the catalytic residue Glu357-->Gln was used for complex crystallization. The structures were refined at accuracies with r.m.s. deviations of bond lengths and bond angles ranging from 0.005A to 0.008A and 1.3 degrees to 1.4 degrees, respectively. The active enzyme forms a dimer in the crystalline state and in solution. The monomer enzyme is composed of four domains, N, A, B and C, and has a (beta/alpha)(8)-barrel in domain A. The active site lies between domain A and domain N from the other monomer. The results show that dimer formation makes the active-site cleft narrower than those of ordinary alpha-amylases, which may contribute to the unique substrate specificity of this enzyme toward both alpha-1,4 and alpha-1,6-glucosidic linkages. This specificity may be influenced by the subsite structure. Only subsites -1 and -2 are commonly occupied by the product and substrates, suggesting that equivocal recognition occurs at the other subsites, which contributes to the wide substrate specificity of this enzyme.
About this StructureAbout this Structure
1J0H is a Single protein structure of sequence from Geobacillus stearothermophilus with and as ligands. Active as Neopullulanase, with EC number 3.2.1.135 Full crystallographic information is available from OCA.
ReferenceReference
Three-dimensional structure and substrate binding of Bacillus stearothermophilus neopullulanase., Hondoh H, Kuriki T, Matsuura Y, J Mol Biol. 2003 Feb 7;326(1):177-88. PMID:12547200
Page seeded by OCA on Thu Feb 21 13:17:40 2008