UDP-Sugar Pyrophosphorylase: A New Old Mechanism for Sugar Activation

Kleczkowski, Leszek A.; Decker, Daniel; Wilczyńska, Małgorzata

doi:10.1104/pp.111.174706

Cited by 50 publications

(44 citation statements)

References 68 publications

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“…On the other hand, Glc-1P is the initial metabolite of routes allowing sugar/NDP-sugar interconversion, synthesis of oligoand polysaccharide structural components, or production of reserve glucans (glycogen) (12,32). A critical point determining metabolic fates for Glc-1P/Glc-6P within a cell is the presence or absence of UDP-sugar PPase, an enzyme that so far has been found in plants and protozoa (15,16,22,26,28,29,41). We omitted this enzyme in the metabolic map detailed in Fig.…”

Section: Figmentioning

confidence: 99%

Characterization of Recombinant UDP- and ADP-Glucose Pyrophosphorylases and Glycogen Synthase To Elucidate Glucose-1-Phosphate Partitioning into Oligo- and Polysaccharides in Streptomyces coelicolor

et al. 2012

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b Streptomyces coelicolor exhibits a major secondary metabolism, deriving important amounts of glucose to synthesize pigmented antibiotics. Understanding the pathways occurring in the bacterium with respect to synthesis of oligo-and polysaccharides is of relevance to determine a plausible scenario for the partitioning of glucose-1-phosphate into different metabolic fates. We report the molecular cloning of the genes coding for UDP-and ADP-glucose pyrophosphorylases as well as for glycogen synthase from genomic DNA of S. coelicolor A3(2). Each gene was heterologously expressed in Escherichia coli cells to produce and purify to electrophoretic homogeneity the respective enzymes. UDP-glucose pyrophosphorylase (UDP-Glc PPase) was characterized as a dimer exhibiting a relatively high V max in catalyzing UDP-glucose synthesis (270 units/mg) and with respect to dTDP-glucose (94 units/mg). ADP-glucose pyrophosphorylase (ADP-Glc PPase) was found to be tetrameric in structure and specific in utilizing ATP as a substrate, reaching similar activities in the directions of ADP-glucose synthesis or pyrophosphorolysis (V max of 0.15 and 0.27 units/mg, respectively). Glycogen synthase was arranged as a dimer and exhibited specificity in the use of ADP-glucose to elongate ␣-1,4-glucan chains in the polysaccharide. ADP-Glc PPase was the only of the three enzymes exhibiting sensitivity to allosteric regulation by different metabolites. Mannose-6-phosphate, phosphoenolpyruvate, fructose-6-phosphate, and glucose-6-phosphate behaved as major activators, whereas NADPH was a main inhibitor of ADP-Glc PPase. The results support a metabolic picture where glycogen synthesis occurs via ADP-glucose in S. coelicolor, with the pathway being strictly regulated in connection with other routes involved with oligo-and polysaccharides, as well as with antibiotic synthesis in the bacterium. Gram-positive bacteria of the genus Streptomyces exhibit a particularly complex morphological differentiation, with the formation of a highly branched substrate and aerial mycelium that generates spores from septation of the aerial hyphae (23, 33). Also characteristic of Streptomyces spp. is the occurrence of a flush secondary metabolism, with these bacteria producing almost twothirds of all known natural antibiotics (9). Streptomyces coelicolor A3(2) is the producer of three pigmented antibiotics, and it has a well-characterized genetics; these characteristics make it one of the preferred strains for research within this genus of bacteria. Although the complete genome of this S. coelicolor strain was elucidated about 10 years ago (5), advanced knowledge of the microorganism at the biochemical level is far from being reached. Most of the studies carried out with Streptomyces spp. have been biased toward the understanding of its morphological and physiological differentiation, while very little has been done on the biochemistry of the enzymes involved in the metabolic pathways.Monosaccharide interconversion and synthesis of oligo-and polysaccharides are key proces...

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Section: Figmentioning

confidence: 99%

Characterization of Recombinant UDP- and ADP-Glucose Pyrophosphorylases and Glycogen Synthase To Elucidate Glucose-1-Phosphate Partitioning into Oligo- and Polysaccharides in Streptomyces coelicolor

et al. 2012

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“…Regarding regulation of UDP-Glc PPases, different posttranscriptional [62] and posttranslational [2,6,63,64] modifications have been reported. In particular, we focus this study on the redox mechanism of regulation.…”

Section: Discussionmentioning

confidence: 98%

The UDP-glucose pyrophosphorylase from Giardia lamblia is redox regulated and exhibits promiscuity to use galactose-1-phosphate

Ebrecht

Diez

Piattoni

et al. 2015

Biochimica et Biophysica Acta (BBA) - General Subjects

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“…Because of this promiscuity, a new EC number (EC 2.7.7.10) was proposed to distinguish it from UTP-glucose-1-phosphate uridylyltransferase (EC 2.7.7.9; GalU), which predominantly acts on G1P in prokaryotes (26,27). However, due to the activity on different sugar 1-phosphates, the absence of similarity with GalU-type enzymes, and a high level of identity with promiscuous eukaryotic uridylyltransferases, we suggest that UgpA should be classified as an UTP-monosaccharide-1-phosphate uridylyltransferase (EC 2.7.7.64, synonym of UDP-sugar pyrophosphorylase [USP]) (28)(29)(30). Moreover, a UDP-sugar pyrophosphorylase from B. longum (BLUSP) was recently cloned, showing 82% amino acid identity with UgpA, and was used for the efficient synthesis of a variety of UDP-sugars (31).…”

Section: Resultsmentioning

confidence: 99%

Unraveling the Leloir Pathway of Bifidobacterium bifidum: Significance of the Uridylyltransferases

Bruyn

Beauprez

Maertens

et al. 2013

Appl Environ Microbiol

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The GNB/LNB (galacto-N-biose/lacto-N-biose) pathway plays a crucial role in bifidobacteria during growth on human milk or mucin from epithelial cells. It is thought to be the major route for galactose utilization in Bifidobacterium longum as it is an energy-saving variant of the Leloir pathway. Both pathways are present in B. bifidum, and galactose 1-phosphate (gal1P) is considered to play a key role. Due to its toxic nature, gal1P is further converted into its activated UDP-sugar through the action of poorly characterized uridylyltransferases. In this study, three uridylyltransferases (galT1, galT2, and ugpA) from Bifidobacterium bifidum were cloned in an Escherichia coli mutant and screened for activity on the key intermediate gal1P. GalT1 and GalT2 showed UDP-glucose-hexose-1-phosphate uridylyltransferase activity (EC 2.7.7.12), whereas UgpA showed promiscuous UTP-hexose-1-phosphate uridylyltransferase activity (EC 2.7.7.10). The activity of UgpA toward glucose 1-phosphate was about 33-fold higher than that toward gal1P. GalT1, as part of the bifidobacterial Leloir pathway, was about 357-fold more active than GalT2, the functional analog in the GNB/LNB pathway. These results suggest that GalT1 plays a more significant role than previously thought and predominates when B. bifidum grows on lactose and human milk oligosaccharides. GalT2 activity is required only during growth on substrates with a GNB core such as mucin glycans.

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UDP-Sugar Pyrophosphorylase: A New Old Mechanism for Sugar Activation

Cited by 50 publications

References 68 publications

Characterization of Recombinant UDP- and ADP-Glucose Pyrophosphorylases and Glycogen Synthase To Elucidate Glucose-1-Phosphate Partitioning into Oligo- and Polysaccharides in Streptomyces coelicolor

Characterization of Recombinant UDP- and ADP-Glucose Pyrophosphorylases and Glycogen Synthase To Elucidate Glucose-1-Phosphate Partitioning into Oligo- and Polysaccharides in Streptomyces coelicolor

The UDP-glucose pyrophosphorylase from Giardia lamblia is redox regulated and exhibits promiscuity to use galactose-1-phosphate

Unraveling the Leloir Pathway of Bifidobacterium bifidum: Significance of the Uridylyltransferases

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