Refine your search:     
Report No.

Structural and functional characterization of the ${it Geobacillus}$ copper nitrite reductase; Involvement of the unique N-terminal region in the interprotein electron transfer with its redox partner

Fukuda, Yota*; Koteishi, Hiroyasu*; Yoneda, Ryohei*; Tamada, Taro; Takami, Hideto*; Inoue, Tsuyoshi*; Nojiri, Masaki

The crystal structures of copper-containing nitrite reductase (CuNiR) from the thermophilic Gram-positive bacterium ${it Geobacillus kaustophilus}$ HTA426 and the amino (N)-terminal 68 residue-deleted mutant were determined at resolutions of 1.3${AA}$ and 1.8${AA}$, respectively. Both structures show a striking resemblance with the overall structure of the well-known CuNiRs composed of two Greek key $$beta$$-barrel domains; however, a remarkable structural difference was found in the N-terminal region. The unique region has one $$beta$$-strand and one $$alpha$$-helix extended to the northern surface of the type-1 copper site. The superposition of the ${it Geobacillus}$ CuNiR model on the electron-transfer complex structure of CuNiR with the redox partner cytochrome ${it c$_{551}$}$ in other denitrifier system led us to infer that this region contributes to the transient binding with the partner protein during the interprotein electron transfer reaction in the ${it Geobacillus}$ system. Furthermore, electron-transfer kinetics experiments using N-terminal residue-deleted mutant and the redox partner, ${it Geobacillus}$ cytochrome ${it c$_{551}$}$, were carried out. These structural and kinetics studies demonstrate that that region is directly involved in the specific partner recognition.



- Accesses




Category:Biochemistry & Molecular Biology



[CLARIVATE ANALYTICS], [WEB OF SCIENCE], [HIGHLY CITED PAPER & CUP LOGO] and [HOT PAPER & FIRE LOGO] are trademarks of Clarivate Analytics, and/or its affiliated company or companies, and used herein by permission and/or license.