Biomaterial Database

Giant DNA virus mimivirus encodes pathway for biosynthesis of unusual sugar 4-amino-4,6-dideoxy-D-glucose (Viosamine). 2012

Francesco Piacente, and Margherita Marin, and Antonio Molinaro, and Cristina De Castro, and Virginie Seltzer, and Annalisa Salis, and Gianluca Damonte, and Cinzia Bernardi, and Jean-Michel Claverie, and Chantal Abergel, and Michela Tonetti

Department of Experimental Medicine and Center of Excellence for Biomedical Research, University of Genova, Viale Benedetto XV/1, 16132 Genova, Italy.

Mimivirus is one the largest DNA virus identified so far, infecting several Acanthamoeba species. Analysis of its genome revealed the presence of a nine-gene cluster containing genes potentially involved in glycan formation. All of these genes are co-expressed at late stages of infection, suggesting their role in the formation of the long fibers covering the viral surface. Among them, we identified the L136 gene as a pyridoxal phosphate-dependent sugar aminotransferase. This enzyme was shown to catalyze the formation of UDP-4-amino-4,6-dideoxy-D-glucose (UDP-viosamine) from UDP-4-keto-6-deoxy-D-glucose, a key compound involved also in the biosynthesis of L-rhamnose. This finding further supports the hypothesis that Mimivirus encodes a glycosylation system that is completely independent of the amoebal host. Viosamine, together with rhamnose, (N-acetyl)glucosamine, and glucose, was found as a major component of the viral glycans. Most of the sugars were associated with the fibers, confirming a capsular-like nature of the viral surface. Phylogenetic analysis clearly indicated that L136 was not a recent acquisition from bacteria through horizontal gene transfer, but it was acquired very early during evolution. Implications for the origin of the glycosylation machinery in giant DNA virus are also discussed.

UI	MeSH Term	Description	Entries
D004279	DNA, Viral	Deoxyribonucleic acid that makes up the genetic material of viruses.	Viral DNA
D005814	Genes, Viral	The functional hereditary units of VIRUSES.	Viral Genes,Gene, Viral,Viral Gene
D005944	Glucosamine		2-Amino-2-Deoxyglucose,Dona,Dona S,Glucosamine Sulfate,Hespercorbin,Xicil,2 Amino 2 Deoxyglucose,Sulfate, Glucosamine
D006031	Glycosylation	The synthetic chemistry reaction or enzymatic reaction of adding carbohydrate or glycosyl groups. GLYCOSYLTRANSFERASES carry out the enzymatic glycosylation reactions. The spontaneous, non-enzymatic attachment of reducing sugars to free amino groups in proteins, lipids, or nucleic acids is called GLYCATION (see MAILLARD REACTION).	Protein Glycosylation,Glycosylation, Protein
D000048	Acanthamoeba	A genus of free-living soil amoebae that produces no flagellate stage. Its organisms are pathogens for several infections in humans and have been found in the eye, bone, brain, and respiratory tract.	Acanthamoebas
D000637	Transaminases	A subclass of enzymes of the transferase class that catalyze the transfer of an amino group from a donor (generally an amino acid) to an acceptor (generally a 2-keto acid). Most of these enzymes are pyridoxyl phosphate proteins. (Dorland, 28th ed) EC 2.6.1.	Aminotransferase,Aminotransferases,Transaminase
D014539	Uridine Diphosphate Sugars	Nucleotide-sugars such as uridine-diphosphate glucose or UDP-glucose.	UDP Sugars,Diphosphate Sugars, Uridine,Sugars, UDP,Sugars, Uridine Diphosphate
D056686	Mimiviridae	A family of nucleocytoplasmic, large, double-stranded DNA viruses with extremely complex genomes.	Mimivirus,Acanthamoeba polyphaga mimivirus,Acanthamoeba polyphaga mimiviruses,Mimiviruses
D019143	Evolution, Molecular	The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.	Molecular Evolution,Genetic Evolution,Evolution, Genetic