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1kwk
From Proteopedia
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|PDB= 1kwk |SIZE=350|CAPTION= <scene name='initialview01'>1kwk</scene>, resolution 2.20Å | |PDB= 1kwk |SIZE=350|CAPTION= <scene name='initialview01'>1kwk</scene>, resolution 2.20Å | ||
|SITE= | |SITE= | ||
| - | |LIGAND= <scene name='pdbligand= | + | |LIGAND= <scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=GAL:BETA-D-GALACTOSE'>GAL</scene>, <scene name='pdbligand=MPD:(4S)-2-METHYL-2,4-PENTANEDIOL'>MPD</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</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] | + | |ACTIVITY= <span class='plainlinks'>[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] </span> |
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY=[[1kwg|1KWG]] | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1kwk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1kwk OCA], [http://www.ebi.ac.uk/pdbsum/1kwk PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1kwk RCSB]</span> | ||
}} | }} | ||
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[[Category: Shoun, H.]] | [[Category: Shoun, H.]] | ||
[[Category: Wakagi, T.]] | [[Category: Wakagi, T.]] | ||
| - | [[Category: ACT]] | ||
| - | [[Category: CL]] | ||
| - | [[Category: GAL]] | ||
| - | [[Category: MPD]] | ||
| - | [[Category: ZN]] | ||
[[Category: galactose complex]] | [[Category: galactose complex]] | ||
[[Category: glycoside hydrolase family 42]] | [[Category: glycoside hydrolase family 42]] | ||
| Line 40: | Line 38: | ||
[[Category: trimer]] | [[Category: trimer]] | ||
| - | ''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 21:54:37 2008'' |
Revision as of 18:54, 30 March 2008
| |||||||
| , resolution 2.20Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , , , , | ||||||
| Activity: | Beta-galactosidase, with EC number 3.2.1.23 | ||||||
| Related: | 1KWG
| ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| 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
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