3OZU

The Crystal Structure of flavohemoglobin from R. eutrophus in complex with miconazole

3OZU の概要

• エントリーDOI: 10.2210/pdb3ozu/pdb
• 関連するPDBエントリー: 3OZV 3OZW
• 分子名称: Flavohemoprotein, PROTOPORPHYRIN IX CONTAINING FE, FLAVIN-ADENINE DINUCLEOTIDE, ... (6 entities in total)
• 機能のキーワード: globin fold, antiparallel beta-barrel, alpha/beta fold, hem-, fad-, nad- binding domains, lipid binding protein
• 由来する生物種: Ralstonia eutropha (Cupriavidus necator)
• 細胞内の位置: Cytoplasm: P39662
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 46745.01

構造登録者

El Hammi, E.,Warkentin, E.,Demmer, U.,Ermler, U.,Baciou, L. (登録日: 2010-09-27, 公開日: 2011-03-16, 最終更新日: 2023-09-06)

主引用文献

El Hammi, E.,Warkentin, E.,Demmer, U.,Limam, F.,Marzouki, N.M.,Ermler, U.,Baciou, L.
Structure of Ralstonia eutropha Flavohemoglobin in Complex with Three Antibiotic Azole Compounds.
Biochemistry, 50:1255-1264, 2011

PubMed Abstract: Flavohemoglobins (flavoHbs) are enzymes that operate primarily as nitric oxide dioxygenases and shuttle thereby electrons among NAD(P)H, FAD, heme, and a ligated redox-active substrate such as O(2). They function in the bacterial defense against nitrosative stress and are therefore considered as targets for new antibiotic drugs. Recently, azole derivatives were proven to be attractive nitric oxide dioxygenase inhibitors, and to explore their binding characteristics, we determined the X-ray structure of the flavoHb from Ralstonia eutropha in a complex with miconazole (FHP(M)), econazole (FHP(E)), and ketoconazole (FHP(K)). In agreement with UV-vis spectroscopic data, one azole compound binds inside the distal heme pocket and ligates to the heme iron by its imidazole substituent. The two additional substituents, mostly chlorinated phenyl groups, form a series of van der Waals contacts with the protein matrix. Both interactions explain their high affinity for flavoHbs, the binding constants being 2.6, 1.2, and 11.6 μM for miconazole, econazole, and ketoconazole, respectively. The FHP(M) and FHP(Lip) (flavoHbs originally loaded with a phospholipid) structures share an "open" state and the FHP(E) and FHP(K) structures a "closed" state. Although the azole compounds were able to push the lipid out of its binding site, a fatty acid fragment is still bound inside the heme pocket of FHP(E) and FHP(K) and dictates the state of the protein. The ligand-induced open-to-closed transition involves a reorientation of the NADH domain accompanied by conformational changes in the C-terminal arm, helix E, and the CE loop resulting in an encapsulation of the heme-binding pocket. Implications of the observed open-to-closed process on the catalytic cycle are discussed.

PubMed: 21210640
DOI: 10.1021/bi101650q

実験手法

X-RAY DIFFRACTION (2 Å)