4TQG

Crystal structure of Megavirus UDP-GlcNAc 4,6-dehydratase, 5-epimerase Mg534

4TQG の概要

• エントリーDOI: 10.2210/pdb4tqg/pdb
• 分子名称: Putative dTDP-d-glucose 4 6-dehydratase, NADPH DIHYDRO-NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE (3 entities in total)
• 機能のキーワード: nadp binding sugar pathway, sugar binding protein
• 由来する生物種: Megavirus chiliensis
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 37684.77

構造登録者

Jeudy, S.,Piacente, F.,De Castro, C.,Molinaro, A.,Salis, A.,Damonte, G.,Bernardi, C.,Tonetti, M.,Claverie, J.M.,Abergel, C. (登録日: 2014-06-11, 公開日: 2014-06-25, 最終更新日: 2023-12-20)

主引用文献

Piacente, F.,De Castro, C.,Jeudy, S.,Molinaro, A.,Salis, A.,Damonte, G.,Bernardi, C.,Abergel, C.,Tonetti, M.G.
Giant Virus Megavirus chilensis Encodes the Biosynthetic Pathway for Uncommon Acetamido Sugars.
J.Biol.Chem., 289:24428-24439, 2014

PubMed Abstract: Giant viruses mimicking microbes, by the sizes of their particles and the heavily glycosylated fibrils surrounding their capsids, infect Acanthamoeba sp., which are ubiquitous unicellular eukaryotes. The glycans on fibrils are produced by virally encoded enzymes, organized in gene clusters. Like Mimivirus, Megavirus glycans are mainly composed of virally synthesized N-acetylglucosamine (GlcNAc). They also contain N-acetylrhamnosamine (RhaNAc), a rare sugar; the enzymes involved in its synthesis are encoded by a gene cluster specific to Megavirus close relatives. We combined activity assays on two enzymes of the pathway with mass spectrometry and NMR studies to characterize their specificities. Mg534 is a 4,6-dehydratase 5-epimerase; its three-dimensional structure suggests that it belongs to a third subfamily of inverting dehydratases. Mg535, next in the pathway, is a bifunctional 3-epimerase 4-reductase. The sequential activity of the two enzymes leads to the formation of UDP-l-RhaNAc. This study is another example of giant viruses performing their glycan synthesis using enzymes different from their cellular counterparts, raising again the question of the origin of these pathways.

PubMed: 25035429
DOI: 10.1074/jbc.M114.588947

実験手法

X-RAY DIFFRACTION (2.2 Å)