Activation and pathway of glucosylglycerol synthesis in the cyanobacterium Synechocystis sp. PCC 6803

Hagemann, Martin; Erdmann, Norbert

doi:10.1099/00221287-140-6-1427

Cited by 106 publications

(102 citation statements)

References 22 publications

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“…We have evidence that T. thermophilus only possesses the two-step pathway leading to the synthesis of MG (N. Empadinhas, L. Pinto, A. Enke, H. Santos and M. S. da Costa, unpublished results). This two-step pathway is similar to those described for the synthesis of osmolytes like trehalose (Giaever et al, 1988), glucosylglycerol (Hagemann and Erdmann, 1994) and galactosylglycerol (Yokoyama et al, 1987), as all proceed via a phosphorylated intermediate. The existence of a single pathway for the synthesis of MG ) at 50°C for 20 min.…”

Section: Genes and Enzymes For The Synthesis Of Compatible Solutes Frmentioning

confidence: 81%

Compatible solutes of organisms that live in hot saline environments

Santos

Costa

2002

Environmental Microbiology

250

206

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SummaryThe accumulation of organic solutes is a prerequisite for osmotic adjustment of all microorganisms. Thermophilic and hyperthermophilic organisms generally accumulate very unusual compatible solutes namely, di-myo -inositol-phosphate, di-mannosyl-di-myoinositol-phosphate, di-glycerol-phosphate, mannosylglycerate and mannosylglyceramide, which have not been identified in bacteria or archaea that grow at low and moderate temperatures. There is also a growing awareness that some of these compatible solutes may have a role in the protection of cell components against thermal denaturation. Mannosylglycerate and di-glycerol-phosphate have been shown to protect enzymes and proteins from thermal denaturation in vitro as well, or better, than compatible solutes from mesophiles. The pathways leading to the synthesis of some of these compatible solutes from thermophiles and hyperthermophiles have been elucidated. However, large numbers of questions remain unanswered. Fundamental and applied interest in compatible solutes and osmotic adjustment in these organisms, drives research that, will, in the near future, allow us to understand the role of compatible solutes in osmotic protection and thermoprotection of some of the most fascinating organisms known on Earth.

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Section: Genes and Enzymes For The Synthesis Of Compatible Solutes Frmentioning

confidence: 81%

Compatible solutes of organisms that live in hot saline environments

Santos

Costa

2002

Environmental Microbiology

250

206

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“…A search of the P. horikoshii genome revealed an ORF (PH1879) that had 29% sequence similarity with the R. marinus MG synthase. However, the recombinant gene product had no measurable activity for the synthesis of MG. 2 The pathway for the synthesis of MG in P. horikoshii appears to be similar to those described for the synthesis of osmolytes like trehalose (32), glucosylglycerol (33), and galactosylglycerol (34), insofar as all proceed via two-step pathways involving a phosphorylated intermediate. The existence of a single pathway for the synthesis of MG in P. horikoshii instead of the branched pathway of R. marinus probably imposes a lower flexibility on the regulation of MG synthesis in response to osmotic and/or thermal stress.…”

Section: Pathway For Synthesis Of Mannosylglycerate In P Horikoshii mentioning

confidence: 96%

Pathway for the Synthesis of Mannosylglycerate in the Hyperthermophilic Archaeon Pyrococcus horikoshii

Empadinhas¹,

Marugg²,

Borges³

et al. 2001

Journal of Biological Chemistry

111

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The biosynthetic pathway for the synthesis of the compatible solute ␣-mannosylglycerate in the hyperthermophilic archaeon Pyrococcus horikoshii is proposed based on the activities of purified recombinant mannosyl-3-phosphoglycerate (MPG) synthase and mannosyl-3-phosphoglycerate phosphatase. The former activity was purified from cell extracts, and the N-terminal sequence was used to identify the encoding gene in the completely sequenced P. horikoshii genome. This gene, designated PH0927, and a gene immediately downstream (PH0926) were cloned and overexpressed in Escherichia coli. The recombinant product of gene PH0927 catalyzed the synthesis of ␣-mannosyl-3-phosphoglycerate (MPG) from GDP-mannose and D-3-phosphoglycerate retaining the configuration about the anomeric carbon, whereas the recombinant gene product of PH0926 catalyzed the dephosphorylation of mannosyl-3-phosphoglycerate to yield the compatible solute ␣-mannosylglycerate. The MPG synthase and the MPG phosphatase were specific for these substrates. Two genes immediately downstream from mpgs and mpgp were identified as a putative bifunctional phosphomannose isomerase/mannose-1-phosphateguanylyltransferase (PH0925) and as a putative phosphomannose mutase (PH0923). Genes PH0927, PH0926, PH0925, and PH0923 were contained in an operon-like structure, leading to the hypothesis that these genes were under the control of an unknown osmosensing mechanism that would lead to ␣-mannosylglycerate synthesis. Recombinant MPG synthase had a molecular mass of 45,208 Da, a temperature for optimal activity between 90 and 100°C, and a pH optimum between 6.4 and 7.4; the recombinant MPG phosphatase had a molecular mass of 27,958 Da and optimum activity between 95 and 100°C and between pH 5.2 and 6.4. This is the first report of the characterization of MPG synthase and MPG phosphatase and the elucidation of a pathway for the synthesis of mannosylglycerate in an archaeon.

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“…This salt dependence is actually a feature common to the biosynthetic pathways of other osmolytes such as, trehalose, glucosylglycerol, and galactosylglycerol, whose synthesis also occurs by two-step reactions, involving the concerted action of synthases and phosphatases (16,18,38). For instance, the synthesis of glucosylglycerol involves the condensation of ADP glucose and glycerol 3-phosphate to produce glucosylglycerol phosphate, which is subsequently dephosphorylated to yield glucosylglycerol (16). The enzymes involved in these biosynthetic pathways have not been purified or thoroughly characterized, but it has been shown that enzyme activities in crude extracts are strongly activated by potassium and sodium salts (16 -18, 38).…”

Section: Discussionmentioning

confidence: 99%

“…glycerate-By analogy with the known biosynthetic pathways of other sugar derivatives, such as glucosylglycerol (16) and trehalose (38), the terminal reaction in the synthesis of MG should involve a sugar nucleotide as donor of the glycosyl moiety, and a phosphorylated acceptor (3-P-glycerate). From an array of experiments with GDP mannose, UDP mannose, and ADP mannose as donors, and D-3-P-glycerate as acceptor, we were unable to detect the formation of MG in cell extracts prepared from R. marinus grown in medium containing 4% NaCl.…”

Section: Enzymatic Activities Involved In the Synthesis Of Mannosyl-mentioning

confidence: 99%

“…Our knowledge of the biosynthetic pathways for compatible solutes in prokaryotes has increased significantly in recent years to include the synthesis of trehalose (13), ectoine (14,15), glucosylglycerol (16,17), galactosylglycerol (18), cyclic-2,3-bisphosphoglycerate (19,20), and di-myo-inositolphosphate (21,22). Mannosylglycerate, a solute initially identified in a few red algae (23), was recently identified in thermophilic bacteria of the genera Rhodothermus, Thermus (5), Petrotoga (4), and hyperthermophilic archaea of the genera Pyrococcus (3), Thermococcus (8), and Methanothermus (7).…”

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confidence: 99%

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Biosynthesis of Mannosylglycerate in the Thermophilic Bacterium Rhodothermus marinus

Martins¹,

Empadinhas²,

Marugg³

et al. 1999

Journal of Biological Chemistry

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The biosynthetic reaction scheme for the compatible solute mannosylglycerate in Rhodothermus marinus is proposed based on measurements of the relevant enzymatic activities in cell-free extracts and in vivo 13 C labeling experiments. The synthesis of mannosylglycerate proceeded via two alternative pathways; in one of them, GDP mannose was condensed with D-glycerate to produce mannosylglycerate in a single reaction catalyzed by mannosylglycerate synthase, in the other pathway, a mannosyl-3-phosphoglycerate synthase catalyzed the conversion of GDP mannose and D-3-phosphoglycerate into a phosphorylated intermediate, which was subsequently converted to mannosylglycerate by the action of a phosphatase. The enzyme activities committed to the synthesis of mannosylglycerate were not influenced by the NaCl concentration in the growth medium. However, the combined mannosyl-3-phosphoglycerate synthase/phosphatase system required the addition of NaCl or KCl to the assay mixture for optimal activity. The mannosylglycerate synthase enzyme was purified and characterized. Based on partial sequence information, the corresponding mgs gene was identified from a genomic library of R. marinus. In addition, the mgs gene was overexpressed in Escherichia coli with a high yield. The enzyme had a molecular mass of 46,125 Da, and was specific for GDP mannose and D-glycerate. This is the first report of the characterization of a mannosylglycerate synthase.

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Activation and pathway of glucosylglycerol synthesis in the cyanobacterium Synechocystis sp. PCC 6803

Cited by 106 publications

References 22 publications

Compatible solutes of organisms that live in hot saline environments

Compatible solutes of organisms that live in hot saline environments

Pathway for the Synthesis of Mannosylglycerate in the Hyperthermophilic Archaeon Pyrococcus horikoshii

Biosynthesis of Mannosylglycerate in the Thermophilic Bacterium Rhodothermus marinus

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