1ORR

Crystal Structure of CDP-Tyvelose 2-Epimerase complexed with NAD and CDP

1ORR の概要

• エントリーDOI: 10.2210/pdb1orr/pdb
• 分子名称: CDP-tyvelose-2-epimerase, NICOTINAMIDE-ADENINE-DINUCLEOTIDE, CYTIDINE-5'-DIPHOSPHATE, ... (4 entities in total)
• 機能のキーワード: rossmann fold, short-chain dehydrogenase/reductase, isomerase
• 由来する生物種: Salmonella typhi
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 160818.76

構造登録者

Koropatkin, N.M.,Liu, H.,Holden, H.M. (登録日: 2003-03-14, 公開日: 2003-08-26, 最終更新日: 2024-02-14)

主引用文献

Koropatkin, N.M.,Liu, H.W.,Holden, H.M.
High Resolution X-ray Structure of Tyvelose Epimerase from Salmonella typhi
J.Biol.Chem., 278:20874-20881, 2003

PubMed Abstract: Tyvelose epimerase catalyzes the last step in the biosynthesis of tyvelose by converting CDP-d-paratose to CDP-d-tyvelose. This unusual 3,6-dideoxyhexose occurs in the O-antigens of some types of Gram-negative bacteria. Here we describe the cloning, protein purification, and high-resolution x-ray crystallographic analysis of tyvelose epimerase from Salmonella typhi complexed with CDP. The enzyme from S. typhi is a homotetramer with each subunit containing 339 amino acid residues and a tightly bound NAD+ cofactor. The quaternary structure of the enzyme displays 222 symmetry and can be aptly described as a dimer of dimers. Each subunit folds into two distinct lobes: the N-terminal motif responsible for NAD+ binding and the C-terminal region that harbors the binding site for CDP. The analysis described here demonstrates that tyvelose epimerase belongs to the short-chain dehydrogenase/reductase superfamily of enzymes. Indeed, its active site is reminiscent to that observed for UDP-galactose 4-epimerase, an enzyme that plays a key role in galactose metabolism. Unlike UDP-galactose 4-epimerase where the conversion of configuration occurs about C-4 of the UDP-glucose or UDP-galactose substrates, in the reaction catalyzed by tyvelose epimerase, the inversion of stereochemistry occurs at C-2. On the basis of the observed binding mode for CDP, it is possible to predict the manner in which the substrate, CDP-paratose, and the product, CDP-tyvelose, might be accommodated within the active site of tyvelose epimerase.

PubMed: 12642575
DOI: 10.1074/jbc.M301948200

実験手法

X-RAY DIFFRACTION (1.5 Å)