4MHU

Crystal structure of EctD from S. alaskensis with bound Fe

4MHU の概要

• エントリーDOI: 10.2210/pdb4mhu/pdb
• 関連するPDBエントリー: 3EMR 4MHR 4Q5O
• 分子名称: Ectoine hydroxylase, FE (III) ION, N-DODECYL-N,N-DIMETHYLGLYCINATE (3 entities in total)
• 機能のキーワード: jelly-roll or cupin fold, ectoine hydroxylase, ectoine, oxidoreductase
• 由来する生物種: Sphingopyxis alaskensis
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 70836.33

構造登録者

Widderich, N.,Hoeppner, A.,Pittelkow, M.,Heider, J.,Smits, S.H.,Bremer, E. (登録日: 2013-08-30, 公開日: 2014-09-03, 最終更新日: 2024-02-28)

主引用文献

Hoppner, A.,Widderich, N.,Lenders, M.,Bremer, E.,Smits, S.H.
Crystal structure of the ectoine hydroxylase, a snapshot of the active site.
J.Biol.Chem., 289:29570-29583, 2014

PubMed Abstract: Ectoine and its derivative 5-hydroxyectoine are compatible solutes that are widely synthesized by bacteria to cope physiologically with osmotic stress. They also serve as chemical chaperones and maintain the functionality of macromolecules. 5-Hydroxyectoine is produced from ectoine through a stereo-specific hydroxylation, an enzymatic reaction catalyzed by the ectoine hydroxylase (EctD). The EctD protein is a member of the non-heme-containing iron(II) and 2-oxoglutarate-dependent dioxygenase superfamily and is evolutionarily well conserved. We studied the ectoine hydroxylase from the cold-adapted marine ultra-microbacterium Sphingopyxis alaskensis (Sa) and found that the purified SaEctD protein is a homodimer in solution. We determined the SaEctD crystal structure in its apo-form, complexed with the iron catalyst, and in a form that contained iron, the co-substrate 2-oxoglutarate, and the reaction product of EctD, 5-hydroxyectoine. The iron and 2-oxoglutarate ligands are bound within the EctD active site in a fashion similar to that found in other members of the dioxygenase superfamily. 5-Hydroxyectoine, however, is coordinated by EctD in manner different from that found in high affinity solute receptor proteins operating in conjunction with microbial import systems for ectoines. Our crystallographic analysis provides a detailed view into the active site of the ectoine hydroxylase and exposes an intricate network of interactions between the enzyme and its ligands that collectively ensure the hydroxylation of the ectoine substrate in a position- and stereo-specific manner.

PubMed: 25172507
DOI: 10.1074/jbc.M114.576769

実験手法

X-RAY DIFFRACTION (2.56 Å)