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| == Function == | | == Function == |
| [https://www.uniprot.org/uniprot/A0A0B4U8I5_9GAMM A0A0B4U8I5_9GAMM] | | [https://www.uniprot.org/uniprot/A0A0B4U8I5_9GAMM A0A0B4U8I5_9GAMM] |
| <div style="background-color:#fffaf0;">
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| == Publication Abstract from PubMed ==
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| A novel gene was isolated for the first time from a psychrophilic gram-negative bacterium Rahnella sp. R3. The gene encoded a cold-adapted beta-galactosidase (R-beta-Gal). Recombinant R-beta-Gal was expressed in Escherichia coli BL21 (DE3), purified and characterized. R-beta-gal belongs to the glycosyl hydrolase family 42. Circular dichroism spectrometry of the structural stability of R-beta-Gal with respect to temperature indicated that the secondary structures of the enzyme were stable to 45 degrees C. In solution, the enzyme was a homo-trimer and was active at temperatures as low as 4 degrees C. The enzyme did not require the presence of metal ions to be active, but Mg(2+), Mn(2+), and Ca(2+) enhanced its activity slightly, whereas Fe(3+), Zn(2+) and Al(3+) appeared to inactive it. The purified enzyme displayed K(m) values of 6.5 mM for ONPG and 2.2mM for lactose at 4 degrees C. These values were lower than the corresponding K(m)s reported for other cold-adapted beta-Gals.
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| Cloning, expression and structural stability of a cold-adapted beta-galactosidase from Rahnella sp. R3.,Fan Y, Hua X, Zhang Y, Feng Y, Shen Q, Dong J, Zhao W, Zhang W, Jin Z, Yang R Protein Expr Purif. 2015 Nov;115:158-64. doi: 10.1016/j.pep.2015.07.001. Epub, 2015 Jul 3. PMID:26145832<ref>PMID:26145832</ref>
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| From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br>
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| </div>
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| <div class="pdbe-citations 5e9a" style="background-color:#fffaf0;"></div>
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| ==See Also== | | ==See Also== |
| *[[Galactosidase 3D structures|Galactosidase 3D structures]] | | *[[Galactosidase 3D structures|Galactosidase 3D structures]] |
| == References ==
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| <references/>
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| __TOC__ | | __TOC__ |
| </StructureSection> | | </StructureSection> |