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Characterisation of glutamine fructose-6-phosphate amidotransferase (EC 2.6.1.16) and N-acetylglucosamine metabolism in Bifidobacterium.

Foley, Sophie, Stolarczyk, E, Mouni, F, Brassart, C, Vidal, O, Aissi, E, Bouquelet, S and Krzewinski, F (2007) Characterisation of glutamine fructose-6-phosphate amidotransferase (EC 2.6.1.16) and N-acetylglucosamine metabolism in Bifidobacterium. Archives of Microbiology, 189 (2). pp. 157-167. ISSN 0302-8933

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Abstract/Description

Bifidobacterium bifidum, in contrast to other bifido-bacterial species, is auxotrophic for N-acetylglucosamine. Growth experiments revealed assimilation of radiolabelled N-acetylglucosamine in bacterial cell walls and in acetate, an end-product of central metabolism via the bifidobacterial d-fructose-6-phosphate shunt. While supplementation with fructose led to reduced N-acetyl-glucosamine assimilation via the d-fructose-6-phosphate shunt, no significant difference was observed in levels of radiolabelled N-acetylglucosamine incorporated into cell walls. Considering the central role played by glutamine fructose-6-phosphate transaminase (GlmS) in linking the biosynthetic pathway for N-acetylglucosamine to hexose metabolism, the GlmS of Bifidobacterium was characterized. The genes encoding the putative GlmS of B. longum DSM20219 and B. bifidum DSM20082 were cloned and sequenced. Bioinformatic analyses of the predicted proteins revealed 43% amino acid identity with the Escherichia coli GlmS, with conservation of key amino acids in the catalytic domain. The B. longum GlmS was over-produced as a histidine-tagged fusion protein. The purified C-terminal His-tagged GlmS possessed glutamine fructose-6-phosphate amidotransferase activity as demonstrated by synthesis of glucosamine-6-phosphate from fructose-6-phosphate and glutamine. It also possesses an independent glutaminase activity, converting glutamine to glutamate in the absence of fructose-6-phosphate. This is of interest considering the apparently reduced coding potential in bifidobacteria for enzymes associated with glutamine metabolism.

Item Type: Article
Print ISSN: 0302-8933
Electronic ISSN: 1432072X
Uncontrolled Keywords: Bifidobacterium; GlmS; Glutamine fructose-6-phosphate amidotransferase; N-acetylglucosamine; Glutaminase activity;
University Divisions/Research Centres: Faculty of Health, Life & Social Sciences > School of Life Sciences
Dewey Decimal Subjects: 500 Science > 570 Life sciences; biology > 572 Biochemistry
500 Science > 570 Life sciences; biology > 579 Microorganisms, fungi & algae
500 Science > 570 Life sciences; biology > 576 Genetics & evolution
Library of Congress Subjects: Q Science > QD Chemistry
Q Science > QH Natural history > QH426 Genetics
Q Science > QR Microbiology
Item ID: 1739
Depositing User: RAE Import
Date Deposited: 21 Jul 2008 14:58
Last Modified: 14 Feb 2013 15:45
URI: http://researchrepository.napier.ac.uk/id/eprint/1739

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