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

© Daisuke Sasaki et al. 2020..

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 nitro-gen cycle where nitrate is used in place of di-oxy-gen 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 Hyphomicrobium denitrificans strain 1NES1 (Hd 1NES1NiR) 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.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:7

Enthalten in:

IUCrJ - 7(2020), Pt 3 vom: 01. Mai, Seite 557-565

Sprache:

Englisch

Beteiligte Personen:

Sasaki, Daisuke [VerfasserIn]
Watanabe, Tatiana F [VerfasserIn]
Eady, Robert R [VerfasserIn]
Garratt, Richard C [VerfasserIn]
Antonyuk, Svetlana V [VerfasserIn]
Hasnain, S Samar [VerfasserIn]

Links:

Volltext

Themen:

Catalysis
Copper-containing nitrite reductase
Denitrification
Electron transfer
Journal Article
Nitro­gen cycle
Structural biology

Anmerkungen:

Date Revised 13.11.2023

published: Electronic-eCollection

Citation Status PubMed-not-MEDLINE

doi:

10.1107/S2052252520005230

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM310142571