5I5M

Shewanella denitrificans nitrous oxide reductase, Ca2+-reconstituted form

Summary for 5I5M

• Entry DOI: 10.2210/pdb5i5m/pdb
• Descriptor: Nitrous-oxide reductase, CALCIUM ION, (R,R)-2,3-BUTANEDIOL, ... (5 entities in total)
• Functional Keywords: nitrogen cycle nitrous oxide reductase beta-propeller apoprotein, oxidoreductase
• Biological source: Shewanella denitrificans (strain OS217 / ATCC BAA-1090 / DSM 15013)
• Total number of polymer chains: 2
• Total formula weight: 143164.37

Authors

Schneider, L.K.,Einsle, O. (deposition date: 2016-02-15, release date: 2016-03-02, Last modification date: 2024-01-10)

Primary citation

Schneider, L.K.,Einsle, O.
Role of Calcium in Secondary Structure Stabilization during Maturation of Nitrous Oxide Reductase.
Biochemistry, 55:1433-1440, 2016

PubMed Abstract: The copper enzyme nitrous oxide reductase catalyzes the two-electron reduction of nitrous oxide N₂O to dinitrogen N₂. Its maturation largely occurs in the periplasm and includes the insertion of at least one Ca²⁺ ion per monomer. Here we have investigated the role of this structural cation in recombinantly produced apo-N₂OR from Shewanella denitrificans and have determined the three-dimensional structure of the protein by X-ray crystallography. In the absence of Ca²⁺, substantial parts of the enzyme surrounding the binding sites for the copper ions show structural disorder. Reconstitution of the binuclear CuA site was possible in vitro but required the presence of Ca²⁺ ions for a stable insertion of the center. In contrast, an excess of Ca²⁺ prevented copper insertion, and the structural analysis of the Ca²⁺apo form revealed that the cation is sufficient to structure the disordered regions of the protein even in the absence of Cu ions, indicating that the geometry of the two noncanonical copper centers is largely predetermined by the protein structure.

PubMed: 26885878
DOI: 10.1021/acs.biochem.5b01278

Experimental method

X-RAY DIFFRACTION (1.37 Å)