Structures of substrate- and product-bound forms of a multi-domain copper nitrite reductase shed light on the role of domain tethering in protein complexes



Sasaki, Daisuke, Watanabe, Tatiana F, Eady, Robert R, Garratt, Richard C, Antonyuk, Svetlana V ORCID: 0000-0002-2779-9946 and Hasnain, S Samar
(2020) Structures of substrate- and product-bound forms of a multi-domain copper nitrite reductase shed light on the role of domain tethering in protein complexes. IUCrJ, 7 (3). pp. 557-565.

Access the full-text of this item by clicking on the Open Access link.
[thumbnail of hdNiR-IUCrJ.pdf] Text
hdNiR-IUCrJ.pdf - Published Version

Download (1MB) | Preview

Abstract

<jats:p>Copper-containing nitrite reductases (CuNiRs) are found in all three kingdoms of life and play a major role in the denitrification branch of the global nitrogen cycle where nitrate is used in place of dioxygen as an electron acceptor in respiratory energy metabolism. Several C- and N-terminal redox domain tethered CuNiRs have been identified and structurally characterized during the last decade. Our understanding of the role of tethered domains in these new classes of three-domain CuNiRs, where an extra cytochrome or cupredoxin domain is tethered to the catalytic two-domain CuNiRs, has remained limited. This is further compounded by a complete lack of substrate-bound structures for these tethered CuNiRs. There is still no substrate-bound structure for any of the as-isolated wild-type tethered enzymes. Here, structures of nitrite and product-bound states from a nitrite-soaked crystal of the N-terminal cupredoxin-tethered enzyme from the <jats:italic>Hyphomicrobium denitrificans</jats:italic> strain 1NES1 (<jats:italic>Hd</jats:italic> <jats:sub>1NES1</jats:sub>NiR) are provided. These, together with the as-isolated structure of the same species, provide clear evidence for the role of the N-terminal peptide bearing the conserved His27 in water-mediated anchoring of the substrate at the catalytic T2Cu site. Our data indicate a more complex role of tethering than the intuitive advantage for a partner-protein electron-transfer complex by narrowing the conformational search in such a combined system.</jats:p>

Item Type: Article
Uncontrolled Keywords: nitrogen cycle, denitrification, copper-containing nitrite reductase, electron transfer, catalysis, structural biology
Depositing User: Symplectic Admin
Date Deposited: 07 May 2020 10:09
Last Modified: 18 Jan 2023 23:52
DOI: 10.1107/s2052252520005230
Open Access URL: https://doi.org/10.1107/S2052252520005230
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3086349