Mannans are polymers containing the sugar mannose as a principal component. They are a type of polysaccharide found in hemicellulose, a major source of biomass found in higher plants such as softwoods. These polymers also typically contain two other sugars, galactose and glucose. They are often branched.
Mannose is a sugar monomer of the aldohexose series of carbohydrates. It is a C-2 epimer of glucose. Mannose is important in human metabolism, especially in the glycosylation of certain proteins. Several congenital disorders of glycosylation are associated with mutations in enzymes involved in mannose metabolism.
3′,5′-cyclic-nucleotide phosphodiesterases (EC 3.1.4.17) are a family of phosphodiesterases. Generally, these enzymes hydrolyze a nucleoside 3′,5′-cyclic phosphate to a nucleoside 5′-phosphate:
Guanylyl transferases are enzymes that transfer a guanosine mono phosphate group, usually from GTP to another molecule, releasing pyrophosphate. Many eukaryotic guanylyl transferases are capping enzymes that catalyze the formation of the 5' cap in the co-transcriptional modification of messenger RNA. Because the 5' end of the RNA molecule ends in a phosphate group, the bond formed between the RNA and the GTP molecule is an unusual 5'-5' triphosphate linkage, instead of the 3'-5' linkages between the other nucleotides that form an RNA strand. In capping enzymes, a highly conserved lysine residue serves as the catalytic residue that forms a covalent enzyme-GMP complex.
Colitose is a mannose-derived 3,6-dideoxysugar produced by certain bacteria. It is a constituent of the lipopolysaccharide. It is the enantiomer of abequose.
Perosamine is a mannose-derived 4-aminodeoxysugar produced by some bacteria.
Mannose-6 phosphate isomerase (MPI), alternately phosphomannose isomerase (PMI) is an enzyme which facilitates the interconversion of fructose 6-phosphate (F6P) and mannose-6-phosphate (M6P). Mannose-6-phosphate isomerase may also enable the synthesis of GDP-mannose in eukaryotic organisms. M6P can be converted to F6P by mannose-6-phosphate isomerase and subsequently utilized in several metabolic pathways including glycolysis and capsular polysaccharide biosynthesis. PMI is monomeric and metallodependent on zinc as a cofactor ligand. PMI is inhibited by erythrose 4-phosphate, mannitol 1-phosphate, and to a lesser extent, the alpha anomer of M6P.
Guanosine diphosphate mannose or GDP-mannose is a nucleotide sugar that is a substrate for glycosyltransferase reactions in metabolism. This compound is a substrate for enzymes called mannosyltransferases.
In enzymology, a guanosine-diphosphatase (EC 3.6.1.42) is an enzyme that catalyzes the chemical reaction
In enzymology, a dolichyl-phosphate beta-D-mannosyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, an undecaprenyl-phosphate mannosyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, an adenosylcobinamide-phosphate guanylyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a fucose-1-phosphate guanylyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a guanylate kinase is an enzyme that catalyzes the chemical reaction
In enzymology, a mannose-1-phosphate guanylyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a mannose-1-phosphate guanylyltransferase (GDP) is an enzyme that catalyzes the chemical reaction
Mannose-1-phosphate guanyltransferase beta is an enzyme that in humans is encoded by the GMPPB gene.
dolichyl-phosphate mannosyltransferase polypeptide 3, also known as DPM3, is a human gene.
Mannosylfructose-phosphate synthase is an enzyme with systematic name GDP-mannose:D-fructose-6-phosphate 2-alpha-D-mannosyltransferase. This enzyme catalyses the following chemical reaction
Adenosylcobinamide-GDP ribazoletransferase is an enzyme with systematic name adenosylcobinamide-GDP:alpha-ribazole ribazoletransferase. This enzyme catalyses the following chemical reaction
