title: Biosynthesis of the tunicamycins: a review.
abstract: Tunicamycins are nucleotide sugar analogs produced by several Streptomyces species. In eukaryotes, tunicamycins inhibit UDP-N-acetylglucosamine: dolichol phosphate GlcNAc-1-P transferase (GPT) that catalyzes the first step in protein glycosylation. In bacteria they inhibit UDP-N-acetylmuramoyl-pentapeptide: undecaprenol phosphate MurNAc-pentapeptide-1-P transtransferase (MraY) that catalyzes an early stage in peptidoglycan cell wall assembly. Tunicamycins are substrate analog of GPT and MraY, such that the alphabeta-1'',11'-linked GlcNAc residue of the tunicamycins mimics the transferred GlcNAc-1-phosphate. The unusual structure of tunicamycins, particularly the unique 11-carbon sugar, tunicamine, and the alphabeta-1'',11'-O-glycosidic linkage, suggest its biosynthesis to be unique. This review discusses potential biosyntheses for tunicamycins via the synthesis and conjugation of uridine-5'-aldehyde and UDP-4-keto-N-acetylgalactosamine-5,6-ene and the subsequent formation of the alpha,beta-1'',11' glycosidic linkage.
authors.affiliation: USDA-ARS-NCAUR, Bioproducts and Biocatalysis Research Unit, 1815 North University Street, Peoria, IL 61604, USA. neil.price@ars.usda.gov
authors.forename: Neil P J
authors.initials: NP
authors.lastname: Price
authors.forename: Billyana
authors.initials: B
authors.lastname: Tsvetanova
mesh_terms: D000447:Aldehydes / Q000378:metabolism; D002236:Carbohydrate Conformation; D004187:Disaccharides; D005688:Galactosamine / Q000031:analogs & derivatives; D006027:Glycosides / Q000378:metabolism; D006031:Glycosylation; D010088:Oxidoreductases / Q000378:metabolism; D019761:Phosphorus-Oxygen Lyases / Q000378:metabolism; D011506:Proteins / Q000378:metabolism; D013302:Streptomyces / Q000378:metabolism; D014415:Tunicamycin / Q000096:biosynthesis* / Q000737:chemistry; D014529:Uridine / Q000378:metabolism