1yq2
From Proteopedia
(New page: 200px<br /><applet load="1yq2" size="450" color="white" frame="true" align="right" spinBox="true" caption="1yq2, resolution 1.90Å" /> '''beta-galactosidase f...) |
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| - | [[Image:1yq2.gif|left|200px]]<br /><applet load="1yq2" size=" | + | [[Image:1yq2.gif|left|200px]]<br /><applet load="1yq2" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1yq2, resolution 1.90Å" /> | caption="1yq2, resolution 1.90Å" /> | ||
'''beta-galactosidase from Arthrobacter sp. C2-2 (isoenzyme C2-2-1)'''<br /> | '''beta-galactosidase from Arthrobacter sp. C2-2 (isoenzyme C2-2-1)'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The X-ray structure of cold-active beta-galactosidase (isoenzyme C-2-2-1) | + | The X-ray structure of cold-active beta-galactosidase (isoenzyme C-2-2-1) from an Antarctic bacterium Arthrobacter sp. C2-2 was solved at 1.9A resolution. The enzyme forms 660 kDa hexamers with active sites opened to the central cavity of the hexamer and connected by eight channels with exterior solvent. To our best knowledge, this is the first cold-active beta-galactosidase with known structure and also the first known beta-galactosidase structure in the form of compact hexamers. The hexamer organization regulates access of substrates and ligands to six active sites and this unique packing, present also in solution, raises questions about its purpose and function. This enzyme belongs to glycosyl hydrolase family 2, similarly to Escherichia coli beta-galactosidase, forming tetramers necessary for its enzymatic function. However, we discovered significant differences between these two enzymes affecting the ability of tetramer/hexamer formation and complementation of the active site. This structure reveals new insights into the cold-adaptation mechanisms of enzymatic pathways of extremophiles. |
==About this Structure== | ==About this Structure== | ||
| - | 1YQ2 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Arthrobacter_sp._1264c Arthrobacter sp. 1264c] with MG, NA, CL, SO4 and PEG as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [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] Full crystallographic information is available from [http:// | + | 1YQ2 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Arthrobacter_sp._1264c Arthrobacter sp. 1264c] with <scene name='pdbligand=MG:'>MG</scene>, <scene name='pdbligand=NA:'>NA</scene>, <scene name='pdbligand=CL:'>CL</scene>, <scene name='pdbligand=SO4:'>SO4</scene> and <scene name='pdbligand=PEG:'>PEG</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [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] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1YQ2 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: glycosyl hydrolase family 2; tim barrel; hexamer]] | [[Category: glycosyl hydrolase family 2; tim barrel; hexamer]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:07:53 2008'' |
Revision as of 14:07, 21 February 2008
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beta-galactosidase from Arthrobacter sp. C2-2 (isoenzyme C2-2-1)
Overview
The X-ray structure of cold-active beta-galactosidase (isoenzyme C-2-2-1) from an Antarctic bacterium Arthrobacter sp. C2-2 was solved at 1.9A resolution. The enzyme forms 660 kDa hexamers with active sites opened to the central cavity of the hexamer and connected by eight channels with exterior solvent. To our best knowledge, this is the first cold-active beta-galactosidase with known structure and also the first known beta-galactosidase structure in the form of compact hexamers. The hexamer organization regulates access of substrates and ligands to six active sites and this unique packing, present also in solution, raises questions about its purpose and function. This enzyme belongs to glycosyl hydrolase family 2, similarly to Escherichia coli beta-galactosidase, forming tetramers necessary for its enzymatic function. However, we discovered significant differences between these two enzymes affecting the ability of tetramer/hexamer formation and complementation of the active site. This structure reveals new insights into the cold-adaptation mechanisms of enzymatic pathways of extremophiles.
About this Structure
1YQ2 is a Single protein structure of sequence from Arthrobacter sp. 1264c with , , , and as ligands. Active as Beta-galactosidase, with EC number 3.2.1.23 Full crystallographic information is available from OCA.
Reference
Cold-active beta-galactosidase from Arthrobacter sp. C2-2 forms compact 660 kDa hexamers: crystal structure at 1.9A resolution., Skalova T, Dohnalek J, Spiwok V, Lipovova P, Vondrackova E, Petrokova H, Duskova J, Strnad H, Kralova B, Hasek J, J Mol Biol. 2005 Oct 21;353(2):282-94. PMID:16171818
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