This view shows enzymes only for those organisms listed below, in the list of taxa known to possess the pathway. If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.
|Superclasses:||Biosynthesis → Other Biosynthesis → Organic Solutes Biosynthesis → Glucosylglycerate Biosynthesis|
Some taxa known to possess this pathway include : Erwinia chrysanthemi , Halomonas elongata , Methanococcoides burtonii , Methanohalophilus portucalensis , Persephonella marina , Synechococcus sp. PCC 7002
Most microorganisms capable of osmotic adaptation accumulate compatible solutes in response to increases in the levels of salts or sugars in the environment.
2-O-(α-D-glucopyranosyl)-D-glycerate (GG) is a rather rare compatible solute that was first identified in the cyanobacterium Synechococcus sp. PCC 7002 (referred to as Agmenellum quadruplicatum in the text) [Kollman79]. Following that initial discovery, GG was observed in the archaeon Methanohalophilus portucalensis strain FDF-1 [Robertson92, Robertson92], and in several bacteria, including a salt-sensitive mutant of the γ-proteobacterium Halomonas elongata [Canovas99], in the γ-proteobacterium Erwinia chrysanthemi [Goude04], and in the thermophilic and slightly halophilic bacterium Persephonella marina, that belongs to the Aquificae class [Costa07].
The role of GG as a compatible solute during osmotic stress has not been verified in most of these organisms, but has been demonstrated unequivocally in Erwinia chrysanthemi under nitrogen limiting conditions. When nitrogen concentration is high the organism synthesizes mostly other, nitrogen-containing compatible solutes (L-glutamate and L-glutamine). It has been suggested that GG may also accumulate in the other organisms during salt stress only under nitrogen-limiting conditions [Goude04].
Two pathways are known for the biosynthesis pf GG, a two-step pathway which is described here, and a single-step pathway described in glucosylglycerate biosynthesis II.
About This Pathway
The two-step pathway for the synthesis of GG has been investigated in Methanococcoides burtonii, and found to be very similar to the pathway for the biosynthesis of 2-O-α-mannosyl-D-glycerate, a related compatible solute found in thermophilic organisms (see mannosylglycerate biosynthesis I) [Costa06]. Both compounds are synthesized in two steps. In GG biosynthesis GDP-α-D-glucose and 3-phospho-D-glycerate are condensed by glucosyl-3-phosphoglycerate synthase, forming 2-O-(α-D-glucopyranosyl)-3-phospho-D-glycerate, which is subsequently dephosphorylated to GG by glucosyl-3-phosphoglycerate phosphatase.
Despite their similar functions, the enzymes catalyzing the first steps in the pathways for 2-O-α-mannosyl-D-glycerate and 2-O-(α-D-glucopyranosyl)-D-glycerate share no sequence homology, and are specific for their respective substrate. On the other hand, the enzymes catalyzing the second steps of the pathways can accept both mannosyl-3-phosphoglycerate and 2-O-(α-D-glucopyranosyl)-3-phospho-D-glycerate, indicating that these phosphatases recognize a common determinant in these substrates, probably the glycerylphosphate moiety.
Variants: glucosylglycerate biosynthesis II
Canovas99: Canovas D, Borges N, Vargas C, Ventosa A, Nieto JJ, Santos H (1999). "Role of Ngamma-acetyldiaminobutyrate as an enzyme stabilizer and an intermediate in the biosynthesis of hydroxyectoine." Appl Environ Microbiol 65(9);3774-9. PMID: 10473374
Costa06: Costa J, Empadinhas N, Goncalves L, Lamosa P, Santos H, da Costa MS (2006). "Characterization of the biosynthetic pathway of glucosylglycerate in the archaeon Methanococcoides burtonii." J Bacteriol 188(3);1022-30. PMID: 16428406
Costa07: Costa J, Empadinhas N, da Costa MS (2007). "Glucosylglycerate biosynthesis in the deepest lineage of the Bacteria: characterization of the thermophilic proteins GpgS and GpgP from Persephonella marina." J Bacteriol 189(5);1648-54. PMID: 17189358
Goude04: Goude R, Renaud S, Bonnassie S, Bernard T, Blanco C (2004). "Glutamine, glutamate, and alpha-glucosylglycerate are the major osmotic solutes accumulated by Erwinia chrysanthemi strain 3937." Appl Environ Microbiol 70(11);6535-41. PMID: 15528516
Kollman79: Kollman, V.H., Hanners, J.L., London, R.E., Adame, E.G., Walker, T.E. (1979). "Photosynthetic preparation and characterization of 13C-labeled carbohydrates in Agmenellum quadruplicatum." Carbohydr Res 73:193-202.
Robertson92: Robertson DE, Lai MC, Gunsalus RP, Roberts MF (1992). "Composition, Variation, and Dynamics of Major Osmotic Solutes in Methanohalophilus Strain FDF1." Appl Environ Microbiol 58(8);2438-2443. PMID: 16348748
Empadinhas08: Empadinhas N, Albuquerque L, Mendes V, Macedo-Ribeiro S, da Costa MS (2008). "Identification of the mycobacterial glucosyl-3-phosphoglycerate synthase." FEMS Microbiol Lett 280(2);195-202. PMID: 18221489
Gest08: Gest P, Kaur D, Pham HT, van der Woerd M, Hansen E, Brennan PJ, Jackson M, Guerin ME (2008). "Preliminary crystallographic analysis of GpgS, a key glucosyltransferase involved in methylglucose lipopolysaccharide biosynthesis in Mycobacterium tuberculosis." Acta Crystallogr Sect F Struct Biol Cryst Commun 64(Pt 12);1121-4. PMID: 19052364
Kaur09: Kaur D, Pham H, Larrouy-Maumus G, Riviere M, Vissa V, Guerin ME, Puzo G, Brennan PJ, Jackson M (2009). "Initiation of methylglucose lipopolysaccharide biosynthesis in mycobacteria." PLoS One 4(5);e5447. PMID: 19421329
Pereira08: Pereira PJ, Empadinhas N, Albuquerque L, Sa-Moura B, da Costa MS, Macedo-Ribeiro S (2008). "Mycobacterium tuberculosis glucosyl-3-phosphoglycerate synthase: structure of a key enzyme in methylglucose lipopolysaccharide biosynthesis." PLoS One 3(11);e3748. PMID: 19015727
Siffert84: Siffert W, Fox G, Gros G (1984). "The effect of carbonic anhydrase inhibition on the velocity of thrombin-stimulated platelet aggregation under physiological conditions." Biochem Biophys Res Commun 121(1);266-70. PMID: 6428406
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