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Characterization of a UDP-N-acetylglucosamine biosynthetic pathway encoded by the giant DNA virus Mimivirus
- Source :
- Glycobiology. 24:51-61
- Publication Year :
- 2013
- Publisher :
- Oxford University Press (OUP), 2013.
-
Abstract
- Mimivirus is a giant DNA virus belonging to the Megaviridae family and infecting unicellular Eukaryotes of the genus Acanthamoeba. The viral particles are characterized by heavily glycosylated surface fibers. Several experiments suggest that Mimivirus and other related viruses encode an autonomous glycosylation system, forming viral glycoproteins independently of their host. In this study, we have characterized three Mimivirus proteins involved in the de novo uridine diphosphate-N-acetylglucosamine (UDP-GlcNAc) production: a glutamine-fructose-6-phosphate transaminase (CDS L619), a glucosamine-6-phosphate N-acetyltransferase (CDS L316) and a UDP-GlcNAc pyrophosphorylase (CDS R689). Sequence and enzymatic analyses have revealed some unique features of the viral pathway. While it follows the eukaryotic-like strategy, it also shares some properties of the prokaryotic pathway. Phylogenetic analyses revealed that the Megaviridae enzymes cluster in monophyletic groups, indicating that they share common ancestors, but did not support the hypothesis of recent acquisitions from one of the known hosts. Rather, viral clades branched at deep nodes in phylogenetic trees, forming independent clades outside sequenced cellular organisms. The intermediate properties between the eukaryotic and prokaryotic pathways, the phylogenetic analyses and the fact that these enzymes are shared between most of the known members of the Megaviridae family altogether suggest that the viral pathway has an ancient origin, resulting from lateral transfers of cellular genes early in the Megaviridae evolution, or from vertical inheritance from a more complex cellular ancestor (reductive evolution hypothesis). The identification of a virus-encoded UDP-GlcNAc pathway reinforces the concept that GlcNAc is a ubiquitous sugar representing a universal and fundamental process in all organisms.
- Subjects :
- Glycosylation
Gene Transfer, Horizontal
Evolution
glucosamine-6P acetyltransferase
Gene Transfer
Acanthamoeba
Biochemistry
Horizontal
Evolution, Molecular
Viral Proteins
chemistry.chemical_compound
Megaviridae
UDP-N-acetylglucosamine
Clade
Gene
UDP-N-acetylglucosamine pyrophosphorylase
Phylogeny
Genetics
Mimivirus
biology
Phylogenetic tree
Molecular
DNA virus
glutamine-fructose-6P transaminase
Mimiviridae
Uridine Diphosphate N-Acetylmuramic Acid
biology.organism_classification
Virology
chemistry
Subjects
Details
- ISSN :
- 14602423 and 09596658
- Volume :
- 24
- Database :
- OpenAIRE
- Journal :
- Glycobiology
- Accession number :
- edsair.doi.dedup.....6004286a2f80427e0d80f6f3693183c3