Structure and Function of the Engineered Multicopper Oxidase CueO from Escherichia coli-Deletion of the Methionine-Rich Helical Region Covering the Substrate-Binding Site
スポンサーリンク
概要
- 論文の詳細を見る
CueO is a multicopper oxidase (MCO) that is involved in the homeostasis of Cu in Escherichia coli and is the sole cuprous oxidase to have ever been found. Differing from other MCOs, the substrate-binding site of CueO is deeply buried under a methionine-rich helical region including α-helices 5, 6, and 7 that interfere with the access of organic substrates. We deleted the region Pro357-His406 and replaced it with a Gly-Gly linker. The crystal structures of a truncated mutant in the presence and in the absence of excess Cu(II) indicated that the scaffold of the CueO molecule and metal-binding sites were reserved in comparison with those of CueO. In addition, the high thermostability of the protein molecule and its spectroscopic and magnetic properties due to four Cu centers were also conserved after truncation. As for functions, the cuprous oxidase activity of the mutant was reduced to ca 10% that of recombinant CueO owing to the decrease in the affinity of the labile Cu site for Cu(I) ions, although activities for laccase substrates such as 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), p-phenylenediamine, and 2,6-dimethoxyphenol increased due to changes in the access of these organic substrates to the type I Cu site. The present engineering of CueO indicates that the methionine-rich α-helices function as a barrier to the access of bulky organic substrates, which provides CueO with specificity as a cuprous oxidase. © 2007 Elsevier Ltd. All rights reserved.
- 2007-10-12
論文 | ランダム
- K-Absorption by Photon Excitation Method of Co and Its Compounds : X-RAY AND XUV ABSORPTION SPECTRA
- 衣生活と結びついた色彩嗜好の実態(第3報)
- 衣生活と結びついた色彩嗜好の実態(第2報)
- Difference in Hepatic Accumulation of Perfluorocarboxylic Acids with Different Carbon Chain Length in Rats(PROCEEDINGS OF 24TH SYMPOSIUM ON TOXICOLOGY AND ENVIRONMENTAL HEALTH)
- 衣生活と結びついた色彩嗜好の実態(第1報)