1kwk
From Proteopedia
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- | [[Image:1kwk.jpg|left|200px]] | + | [[Image:1kwk.jpg|left|200px]] |
- | + | ||
- | '''Crystal structure of Thermus thermophilus A4 beta-galactosidase in complex with galactose''' | + | {{Structure |
+ | |PDB= 1kwk |SIZE=350|CAPTION= <scene name='initialview01'>1kwk</scene>, resolution 2.20Å | ||
+ | |SITE= | ||
+ | |LIGAND= <scene name='pdbligand=GAL:BETA-D-GALACTOSE'>GAL</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene> and <scene name='pdbligand=MPD:(4S)-2-METHYL-2,4-PENTANEDIOL'>MPD</scene> | ||
+ | |ACTIVITY= [http://en.wikipedia.org/wiki/Beta-galactosidase Beta-galactosidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.23 3.2.1.23] | ||
+ | |GENE= | ||
+ | }} | ||
+ | |||
+ | '''Crystal structure of Thermus thermophilus A4 beta-galactosidase in complex with galactose''' | ||
+ | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
- | 1KWK is a [ | + | 1KWK is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Thermus_thermophilus Thermus thermophilus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1KWK OCA]. |
==Reference== | ==Reference== | ||
- | Trimeric crystal structure of the glycoside hydrolase family 42 beta-galactosidase from Thermus thermophilus A4 and the structure of its complex with galactose., Hidaka M, Fushinobu S, Ohtsu N, Motoshima H, Matsuzawa H, Shoun H, Wakagi T, J Mol Biol. 2002 Sep 6;322(1):79-91. PMID:[http:// | + | Trimeric crystal structure of the glycoside hydrolase family 42 beta-galactosidase from Thermus thermophilus A4 and the structure of its complex with galactose., Hidaka M, Fushinobu S, Ohtsu N, Motoshima H, Matsuzawa H, Shoun H, Wakagi T, J Mol Biol. 2002 Sep 6;322(1):79-91. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/12215416 12215416] |
[[Category: Beta-galactosidase]] | [[Category: Beta-galactosidase]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
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[[Category: trimer]] | [[Category: trimer]] | ||
- | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 12:23:09 2008'' |
Revision as of 10:23, 20 March 2008
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, resolution 2.20Å | |||||||
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Ligands: | , , , and | ||||||
Activity: | Beta-galactosidase, with EC number 3.2.1.23 | ||||||
Coordinates: | save as pdb, mmCIF, xml |
Crystal structure of Thermus thermophilus A4 beta-galactosidase in complex with galactose
Overview
The beta-galactosidase from an extreme thermophile, Thermus thermophilus A4 (A4-beta-Gal), is thermostable and belongs to the glycoside hydrolase family 42 (GH-42). As the first known structures of a GH-42 enzyme, we determined the crystal structures of free and galactose-bound A4-beta-Gal at 1.6A and 2.2A resolution, respectively. A4-beta-Gal forms a homotrimeric structure resembling a flowerpot. Each monomer has an active site located inside a large central tunnel. The N-terminal domain of A4-beta-Gal has a TIM barrel fold, as predicted from hydrophobic cluster analysis. The putative catalytic residues of A4-beta-Gal (Glu141 and Glu312) superimpose well with the catalytic residues of Escherichia coli beta-galactosidase. The environment around the catalytic nucleophile (Glu312) is similar to that in the case of E.coli beta-galactosidase, but the recognition mechanism for a substrate is different. Trp182 of the next subunit of the trimer constitutes a part of the active-site pocket, indicating that the trimeric structure is essential for the enzyme activity. Structural comparison with other glycoside hydrolases revealed that many features of the 4/7 superfamily are conserved in the A4-beta-Gal structure. On the basis of the results of 1H NMR spectroscopy, A4-beta-Gal was determined to be a "retaining" enzyme. Interestingly, the active site was similar with those of retaining enzymes, but the overall fold of the TIM barrel domain was very similar to that of an inverting enzyme, beta-amylase.
About this Structure
1KWK is a Single protein structure of sequence from Thermus thermophilus. Full crystallographic information is available from OCA.
Reference
Trimeric crystal structure of the glycoside hydrolase family 42 beta-galactosidase from Thermus thermophilus A4 and the structure of its complex with galactose., Hidaka M, Fushinobu S, Ohtsu N, Motoshima H, Matsuzawa H, Shoun H, Wakagi T, J Mol Biol. 2002 Sep 6;322(1):79-91. PMID:12215416
Page seeded by OCA on Thu Mar 20 12:23:09 2008
Categories: Beta-galactosidase | Single protein | Thermus thermophilus | Fushinobu, S. | Hidaka, M. | Matsuzawa, H. | Motoshima, H. | Ohtsu, N. | Shoun, H. | Wakagi, T. | ACT | CL | GAL | MPD | ZN | Galactose complex | Glycoside hydrolase family 42 | Tim barrel | Trimer