GDP-mannose

Figure 47-7. Pathway of biosynthesis of dolichol-P-P-oligosaccharide. The specific linkages formed are indicated in Figure 47-8. Note that the first five internal mannose residues are donated by GDP-mannose, whereas the more external mannose residues and the glucose residues are donated by dolichol-P-mannose and dolichol-P-glucose. (UDP, uridine diphosphate Dol, dolichol P, phosphate UMP, uridine monophosphate GDP, guanosine diphosphate M, mannose G, glucose.)...

Page 207, line 2. GDP-mannose has been isolated from hen-oviduct extracts.11 ... 

The following is a review on the molecular and physical properties of this enzyme [EC 4.2.1.47] which catalyzes the dehydration of GDP-mannose to yield GDP-4-dehy-dro-6-deoxy-D-mannose and water. 

This enzyme [EC 2.4.1.83] which catalyzes the following reaction GDP-mannose + dolichyl phosphate to yield GDP -h dolichyl D-mannosyl phosphate. 

This set of enzymes represent transferases that utilize GDP -mannose ... 

Glucomannan 4-/3-mannosyltransferase [EC 2.4.1.32] catalyzes the reaction of GDP-mannose with [glucoman-nan] to produce GDP and [glucomannan]( +1). 

Phosphatidyl-myo-inositol a-mannosyltransferase [EC 2.4.1.57] catalyzes the transfer of one or more a-o-man-nose units from GDP-mannose to positions 2, 6, and others in 1-phosphatidyl-myo-mositol. 

Glycolipid 2-a-mannosyltransferase [EC 2.4.1.131] catalyzes the transfer of an a-o-mannosyl residue from GDP-mannose into a lipid-Unked ohgosaccharide, forming an a-l,2-D-mannosyl-D-mannose hnkage. The two 1,2-linked mannosyl residues in the mammalian hpid-lmked... 

This enzyme [EC 2.7.7.13], also known as GTP-mannose-1-phosphate guanylyltransferase, catalyzes the reaction of GTP with a-D-mannose 1-phosphate to produce GDP-mannose and pyrophosphate (or, diphosphate). The bacterial enzyme can also use ITP and dGTP as the phospho-ryl donors. 

Scheme 1. — Reactions Involved in the Biosynthesis of D-Mannan from GDP-Mannose. [The acceptor lipid in the reaction, undecaprenyl phosphate, is designated as follows ]...

Plants form ascorbate from GDP-mannose via GDP-L-galactose, L-galactose and L-galactono-1,4-lactone. The latter is oxidized to L-ascorbic acid by a mitochondrial L-galactono-1,4-lactone dehydrogenase, using cytochrome c as electron acceptor. The biosyntheis of L-ascorbic acid has been reviewed.337... 

Wittmann V, Wong C-H (1997) H-Tetrazole as catalyst in phosphomorpholidate coupling reactions efficient synthesis of GDP-fucose, GDP-mannose, and UDP-galactose. J Org Chem 62 2144... 

Mizanur RM, Pohl NLB (2009) Phosphomannose isomerase/GDP-mannose pyrophosphory-lase from Pyrococcus furiosus a thermostable biocatalyst for the synthesis of guanidinedi-phosphate-activated and mannose-containing sugar nucleotides. Org Biomol Chem 7 2135-2139... 

Conklin PL, Norris SR, Wheeler GL et al (1999) Genetic evidence for the role of GDP-mannose in plant ascorbic acid (vitamin C) biosynthesis. Proc Natl Acad Sci USA 96 4198-4203... 

Sugiyama, T., Kido, N., Komatsu, T., Ohta, M., Jann, K., Jann, B., Saeki, A., Kato, N. Genetic analysis of Escherichia coli 09 rfb identification and DNA sequence of phos-phomannomutase and GDP-mannose pyrophosphorylase genes. Microbiology 140 (1994) 59-71. 

The putative pathway of coordination of mannan and PolyP biosynthesis by cell-wall formation has been proposed (Kulaev, 1994), which explains the presence of PolyP outside of the cytoplasmic membrane (Figure 7.4). Dolichyl-phosphates (Dol-Ps) act as transmembrane carriers of carbohydrate residues in glycoprotein biosynthesis. GDP-mannose at the... 

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