6VO8

X-ray structure of the Cj1427 in the presence of NADH and GDP-D-glycero-D-mannoheptose, an essential NAD-dependent dehydrogenase from Campylobacter jejuni

6VO8 の概要

• エントリーDOI: 10.2210/pdb6vo8/pdb
• 関連するPDBエントリー: 6vo6
• 分子名称: Putative sugar-nucleotide epimerase/dehydratease, 1,4-DIHYDRONICOTINAMIDE ADENINE DINUCLEOTIDE, [[(2~{R},3~{S},4~{R},5~{R})-5-(2-azanyl-6-oxidanylidene-3~{H}-purin-9-yl)-3,4-bis(oxidanyl)oxolan-2-yl]methoxy-oxidanyl-phosphoryl] [(2~{R},3~{S},4~{S},5~{S},6~{S})-6-[(1~{S})-1,2-bis(oxidanyl)ethyl]-3,4,5-tris(oxidanyl)oxan-2-yl] hydrogen phosphate, ... (4 entities in total)
• 機能のキーワード: capsular polysaccharide, oxidoreductase, dehydrogenase, isomerase
• 由来する生物種: Campylobacter jejuni subsp. jejuni serotype O:2 (strain ATCC 700819 / NCTC 11168)
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 76040.18

構造登録者

Spencer, K.D.,Anderson, T.K.,Thoden, J.B.,Huddleston, J.P.,Raushel, F.M.,Holden, H.M. (登録日: 2020-01-30, 公開日: 2020-03-25, 最終更新日: 2023-10-11)

主引用文献

Huddleston, J.P.,Anderson, T.K.,Spencer, K.D.,Thoden, J.B.,Raushel, F.M.,Holden, H.M.
Structural Analysis of Cj1427, an Essential NAD-Dependent Dehydrogenase for the Biosynthesis of the Heptose Residues in the Capsular Polysaccharides ofCampylobacter jejuni.
Biochemistry, 59:1314-1327, 2020

PubMed Abstract: Many strains of display modified heptose residues in their capsular polysaccharides (CPS). The precursor heptose was previously shown to be GDP-d--α-d--heptose, from which a variety of modifications of the sugar moiety have been observed. These modifications include the generation of 6-deoxy derivatives and alterations of the stereochemistry at C3-C6. Previous work has focused on the enzymes responsible for the generation of the 6-deoxy derivatives and those involved in altering the stereochemistry at C3 and C5. However, the generation of the 6-hydroxyl heptose residues remains uncertain due to the lack of a specific enzyme to catalyze the initial oxidation at C4 of GDP-d--α-d--heptose. Here we reexamine the previously reported role of Cj1427, a dehydrogenase found in NTCC 11168 (HS:2). We show that Cj1427 is co-purified with bound NADH, thus hindering catalysis of oxidation reactions. However, addition of a co-substrate, α-ketoglutarate, converts the bound NADH to NAD. In this form, Cj1427 catalyzes the oxidation of l-2-hydroxyglutarate back to α-ketoglutarate. The crystal structure of Cj1427 with bound GDP-d--α-d--heptose shows that the NAD(H) cofactor is ideally positioned to catalyze the oxidation at C4 of the sugar substrate. Additionally, the overall fold of the Cj1427 subunit places it into the well-defined short-chain dehydrogenase/reductase superfamily. The observed quaternary structure of the tetrameric enzyme, however, is highly unusual for members of this superfamily.

PubMed: 32168450
DOI: 10.1021/acs.biochem.0c00096

実験手法

X-RAY DIFFRACTION (2.4 Å)