Reference : Structural, Kinetic, and Calorimetric Characterization of the Cold-Active Phosphoglyc...
Scientific journals : Article
Life sciences : Biochemistry, biophysics & molecular biology
Structural, Kinetic, and Calorimetric Characterization of the Cold-Active Phosphoglycerate Kinase from the Antarctic Pseudomonas Sp. Tacii18
Bentahir, Mostafa [> > > >]
Feller, Georges mailto [Université de Liège - ULiège > Département des sciences de la vie > Labo de biochimie >]
Aittaleb, Mohamed [> > > >]
Lamotte-Brasseur, Josette [> > > >]
Himri, Touhami [> > > >]
Chessa, Jean-Pierre [> > > >]
Gerday, Charles mailto [Université de Liège - ULiège > Services généraux (Faculté des sciences) > Relations académiques et scientifiques (Sciences) >]
Journal of Biological Chemistry
Yes (verified by ORBi)
[en] 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.

File(s) associated to this reference

Fulltext file(s):

Open access
JBC_2000_PGK.pdfNo commentaryPublisher postprint420.78 kBView/Open

Bookmark and Share SFX Query

All documents in ORBi are protected by a user license.