Biology:Nucleotide sugars metabolism

From HandWiki
The nucleotide sugar UDP-galactose.

In nucleotide sugar metabolism a group of biochemicals known as nucleotide sugars act as donors for sugar residues in the glycosylation reactions that produce polysaccharides.[1] They are substrates for glycosyltransferases.[2] The nucleotide sugars are also intermediates in nucleotide sugar interconversions that produce some of the activated sugars needed for glycosylation reactions.[1] Since most glycosylation takes place in the endoplasmic reticulum and golgi apparatus, there are a large family of nucleotide sugar transporters that allow nucleotide sugars to move from the cytoplasm, where they are produced, into the organelles where they are consumed.[3][4]

Nucleotide sugar metabolism is particularly well-studied in yeast,[5] fungal pathogens,[6] and bacterial pathogens, such as E. coli and Mycobacterium tuberculosis, since these molecules are required for the synthesis of glycoconjugates on the surfaces of these organisms.[7][8] These glycoconjugates are virulence factors and components of the fungal and bacterial cell wall. These pathways are also studied in plants, but here the enzymes involved are less well understood.[9]

References

  1. 1.0 1.1 Ginsburg V (1978). "Comparative biochemistry of nucleotide-linked sugars". Prog. Clin. Biol. Res. 23: 595–600. PMID 351635. 
  2. "Glycobiology". Annu Rev Biochem 57: 785–838. 1988. doi:10.1146/annurev.bi.57.070188.004033. PMID 3052290. 
  3. "Nucleotide-sugar transporters: structure, function and roles in vivo". Braz. J. Med. Biol. Res. 39 (9): 1149–58. 2006. doi:10.1590/s0100-879x2006000900002. PMID 16981043. 
  4. "Nucleotide sugar transporters: biological and functional aspects". Biochimie 83 (8): 775–82. 2001. doi:10.1016/S0300-9084(01)01322-0. PMID 11530210. 
  5. "The VRG4 gene is required for GDP-mannose transport into the lumen of the Golgi in the yeast, Saccharomyces cerevisiae.". J. Biol. Chem. 272 (50): 31908–14. 1997. doi:10.1074/jbc.272.50.31908. PMID 9395539. 
  6. Nishikawa A.; Poster J.B.; Jigami Y.; Dean N. (2002). "Molecular and phenotypic analysis of CaVRG4, encoding an essential Golgi apparatus GDP-mannose transporter.". J. Bacteriol. 184 (50): 29–42. doi:10.1128/JB.184.1.29-42.2002. PMID 11741841. 
  7. "Biosynthesis of O-antigens: genes and pathways involved in nucleotide sugar precursor synthesis and O-antigen assembly". Carbohydr. Res. 338 (23): 2503–19. 2003. doi:10.1016/j.carres.2003.07.009. PMID 14670712. 
  8. "Formation of dTDP-rhamnose is essential for growth of mycobacteria". J. Bacteriol. 184 (12): 3392–5. 2002. doi:10.1128/JB.184.12.3392-3395.2002. PMID 12029057. 
  9. Seifert GJ (2004). "Nucleotide sugar interconversions and cell wall biosynthesis: how to bring the inside to the outside". Curr. Opin. Plant Biol. 7 (3): 277–84. doi:10.1016/j.pbi.2004.03.004. PMID 15134748.