Structural, Kinetic, and Calorimetric Characterization of the Cold-Active Phosphoglycerate Kinase from the Antarctic Pseudomonas Sp. Tacii18

peer reviewed The gene encoding the phosphoglycerate kinase (PGK) from the Antarctic Pseudomonas sp. TACII18 has been cloned and found to be inserted between the genes encoding for glyceraldhyde-3-phosphate dehydrogenase and fructose aldolase. The His-tagged and the native recombinant PGK from the p...

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Bibliographic Details
Published in:Journal of Biological Chemistry
Main Authors: Bentahir, Mostafa, Feller, Georges, Aittaleb, Mohamed, Lamotte-Brasseur, Josette, Himri, Touhami, Chessa, Jean-Pierre, Gerday, Charles
Format: Article in Journal/Newspaper
Language:English
Published: American Society for Biochemistry and Molecular Biology 2000
Subjects:
Life sciences
Biochemistry
biophysics & molecular biology
Sciences du vivant
Biochimie
biophysique & biologie moléculaire
Antarc*
Antarctic
Online Access:https://orbi.uliege.be/handle/2268/16106
https://orbi.uliege.be/bitstream/2268/16106/1/JBC_2000_PGK.pdf
https://doi.org/10.1074/jbc.275.15.11147
Description
Summary:peer reviewed The gene encoding the phosphoglycerate kinase (PGK) from the Antarctic Pseudomonas sp. TACII18 has been cloned and found to be inserted between the genes encoding for glyceraldhyde-3-phosphate dehydrogenase and fructose aldolase. The His-tagged and the native recombinant PGK from the psychrophilic Pseudomonas were expressed in Escherichia coli. The wild-type and the native recombinant enzymes displayed identical properties, such as a decreased thermostability and a 2-fold higher catalytic efficiency at 25 degrees C when compared with the mesophilic PGK from yeast. These properties, which reflect typical features of cold-adapted enzymes, were strongly altered in the His-tagged recombinant PGK. The structural model of the psychrophilic PGK indicated that a key determinant of its low stability is the reduced number of salt bridges, surface charges, and aromatic interactions when compared with mesophilic and thermophilic PGK. Differential scanning calorimetry of the psychrophilic PGK revealed unusual variations in its conformational stability for the free and substrate-bound forms. In the free form, a heat-labile and a thermostable domain unfold independently. It is proposed that the heat-labile domain acts as a destabilizing domain, providing the required flexibility around the active site for catalysis at low temperatures.

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