5ZLT

Crystal structure of UDP-GlcNAc 2-epimerase NeuC complexed with UDP

5ZLT の概要

• エントリーDOI: 10.2210/pdb5zlt/pdb
• 分子名称: GDP/UDP-N,N'-diacetylbacillosamine 2-epimerase (Hydrolyzing), SULFATE ION, URIDINE-5'-DIPHOSPHATE, ... (4 entities in total)
• 機能のキーワード: neuc, udp n-acetylglucosamine 2-epimerase, hydrolase
• 由来する生物種: Acinetobacter baumannii
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 170718.56

構造登録者

Ko, T.P.,Hsieh, T.J.,Yang, C.S.,Chen, Y. (登録日: 2018-03-29, 公開日: 2018-05-16, 最終更新日: 2023-11-22)

主引用文献

Ko, T.P.,Lai, S.J.,Hsieh, T.J.,Yang, C.S.,Chen, Y.
The tetrameric structure of sialic acid-synthesizing UDP-GlcNAc 2-epimerase fromAcinetobacter baumannii: A comparative study with human GNE.
J. Biol. Chem., 293:10119-10127, 2018

PubMed Abstract: Sialic acid presentation on the cell surface by some pathogenic strains of bacteria allows their escape from the host immune system. It is one of the major virulence factors. Bacterial biosynthesis of sialic acids starts with the conversion of UDP-GlcNAc to UDP and ManNAc by a hydrolyzing 2-epimerase. Here, we present the crystal structure of this enzyme, named NeuC, from The protein folds into two Rossmann-like domains and forms dimers and tetramers as does the epimerase part of the bifunctional UDP-GlcNAc 2-epimerase/ManNAc kinase (GNE). In contrast to human GNE, which showed only the closed conformation, the NeuC crystals contained both open and closed protomers in each dimer. Substrate soaking changed the space group from C222 to P222 In addition to UDP, an intermediate-like ligand was seen bound to the closed protomer. The UDP-binding mode in NeuC was similar to that in GNE, although a few side chains were rotated away. NeuC lacks the CMP-Neu5Ac-binding site for allosteric inhibition of GNE. However, the two enzymes as well as other NeuC homologues (but not SiaA from ) appear to be common in tetrameric organization. The revised two-base catalytic mechanism may involve His-125 (Glu-134 in GNE), as suggested by mutant activity analysis.

PubMed: 29764940
DOI: 10.1074/jbc.RA118.001971

実験手法

X-RAY DIFFRACTION (2.5 Å)