1yq2
From Proteopedia
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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 MG, NA, CL, SO4 and PEG 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
Page seeded by OCA on Sun Nov 25 04:28:54 2007
