JB Email Content Delivery
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Caescu, C. I.
Right arrow Articles by Bouquelet, S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Caescu, C. I.
Right arrow Articles by Bouquelet, S.
Journal of Bacteriology, October 2004, p. 6515-6525, Vol. 186, No. 19
0021-9193/04/$08.00+0     DOI: 10.1128/JB.186.19.6515-6525.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.

Bifidobacterium longum Requires a Fructokinase (Frk; ATP:D-Fructose 6-Phosphotransferase, EC 2.7.1.4) for Fructose Catabolism

Cristina I. Caescu,1,2 Olivier Vidal,1* Frédéric Krzewinski,1 Vlad Artenie,2 and Stéphane Bouquelet1

Unité de Glycobiologie Structurale et Fonctionnelle, UMR CNRS-USTL 8576, Université des Sciences et Technologies de Lille, Villeneuve d'Ascq, France,1 Laboratorul de Biochimie, Universitatea "Al. I. Cuza," Iasi, Romania2

Received 23 February 2004/ Accepted 28 June 2004

Although the ability of Bifidobacterium spp. to grow on fructose as a unique carbon source has been demonstrated, the enzyme(s) needed to incorporate fructose into a catabolic pathway has hitherto not been defined. This work demonstrates that intracellular fructose is metabolized via the fructose-6-P phosphoketolase pathway and suggests that a fructokinase (Frk; EC 2.7.1.4) is the enzyme that is necessary and sufficient for the assimilation of fructose into this catabolic route in Bifidobacterium longum. The B. longum A10C fructokinase-encoding gene (frk) was expressed in Escherichia coli from a pET28 vector with an attached N-terminal histidine tag. The expressed enzyme was purified by affinity chromatography on a Co2+-based column, and the pH and temperature optima were determined. A biochemical analysis revealed that Frk displays the same affinity for fructose and ATP (Kmfructose = 0.739 ± 0.18 mM and KmATP = 0.756 ± 0.08 mM), is highly specific for D-fructose, and is inhibited by an excess of ATP (>12 mM). It was also found that frk is inducible by fructose and is subject to glucose-mediated repression. Consequently, this work presents the first characterization at the molecular and biochemical level of a fructokinase from a gram-positive bacterium that is highly specific for D-fructose.


* Corresponding author. Mailing address: Unité de Glycobiologie Structurale et Fonctionnelle, UMR CNRS-USTL 8576, Université des Sciences et Technologies de Lille, F-59655 Villeneuve d'Ascq, France. Phone: (33) 3 20 43 41 42. Fax: (33) 3 20 43 65 55. E-mail: olivier.vidal{at}univ-lille1.fr.


Journal of Bacteriology, October 2004, p. 6515-6525, Vol. 186, No. 19
0021-9193/04/$08.00+0     DOI: 10.1128/JB.186.19.6515-6525.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.




This article has been cited by other articles:




Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
Appl. Environ. Microbiol. Infect. Immun. Eukaryot. Cell
Mol. Cell. Biol. J. Virol. Microbiol. Mol. Biol. Rev.
ALL ASM JOURNALS

Copyright © 2004 by the American Society for Microbiology. All rights reserved.