Disease relevance of Sedoheptulose

• The isomerization of sedoheptulose 7-phosphate, into a phosphosugar presumed to be D-glycero-D-mannoheptose 7-phosphate, was detected in enzyme reactions with cell extracts of E. coli lpcA+ and of lpcA mutants containing the recombinant lpcA gene [1].

High impact information on Sedoheptulose

• A scheme is proposed for the regulation of stromal sedoheptulose 1,7-bisphosphatase activity which enlarges upon a previously elaborated mechanism (Woodrow, I.E., and Walker, D.A. (1983) Biochim. Biophys. Acta 722, 508-516) [2].
• Once activated, chloroplast fructose-1,6-bisphosphatase hydrolyzed fructose 1,6-bisphosphate and sedoheptulose 1,7-bisphosphate in the presence of Mg2+, Mn2+, or Fe2+ [3].
• However, sedoheptulose, smaller sugars, and smaller polyols did not stimulate in vitro P22 DNA packaging [4].
• In blood from the TALDO1-deficient patient, sedoheptulose 7-phosphate was increased [5].
• These results suggest that there exists a unique active site for either sedoheptulose 1,7-bisphosphate or fructose 1,6-bisphosphate on the enzyme molecule [6].

Chemical compound and disease context of Sedoheptulose

• The binding was inhibited by mannose, N-acetylglucosamine, N-acetylmannosamine, L-fucose, manno-heptulose, and sedoheptulose, suggesting that MBP recognized L-glycero-D-manno-heptose and N-acetylglucosamine constituting the core oligosaccharide of the E. coli K-12 cell wall, and L-glycero-D-manno-heptose for E. coli B [7].

Anatomical context of Sedoheptulose

• It is based on incubation of erythrocyte hemolysates with radioactive ribose 5-phosphate followed by isolation of sedoheptulose 7-phosphate on anion-exchange columns [8].
• The role of fructose 2,6-bisphosphate in the interconversion of sedoheptulose 7-phosphate and sedoheptulose 1,7-bisphosphate in rat liver cytosol fractions was studied by means of phosphorus magnetic resonance spectroscopy [9].

Associations of Sedoheptulose with other chemical compounds

• This gene resembles acbC from Actinoplanes sp. 50/110, which encodes a C7-cyclitol synthase that catalyses the transformation of sedoheptulose 7-phosphate into 2-5-epi-valiolone for acarbose biosynthesis [10].
• Activities of the key enzymes in the pentose phosphate pathway (transketolase, transaldolase) increased 2-fold while the concentrations of their substrates (pentose 5-phosphates, sedoheptulose 7-phosphate) decreased correspondingly [11].

Gene context of Sedoheptulose

• The net effect is that the quantity of sedoheptulose 7-phosphate formed more precisely represents the transketolase activity, which is unaffected under these conditions [12].
• Chloroplastic sedoheptulose bisphosphatase is activated by thioredoxin fB but not by thioredoxin fA [13].
• Km values for the other physiological substrates of transketolase A were 90 microM for erythrose 4-phosphate (best acceptor substrate), 2.1 mM for D,L-glyceraldehyde 3-phosphate, 1.1 mM for fructose 6-phosphate, and 4 mM for sedoheptulose 7-phosphate [14].
• Role of ferredoxin in the activation of sedoheptulose diphosphatase in isolated chloroplasts [15].
• Accumulation of sedoheptulose 7-phosphate raised the possibility of TAL (transaldolase) deficiency in this patient [16].

References