CHAPTER 3: Structure, Function and Mechanisms of Respiratory Nitrate Reductases

Pablo J. Gonzalez, Maria G. Rivas, José J.G. Moura

Research output: Chapter in Book/Report/Conference proceedingChapter

Abstract

Respiratory nitrate reductases (Nars) are oxidoreductases that depend on complex cofactors that contain different transition metals. Nars are produced by microorganisms that can grow under denitrifying conditions and catalyse the first step of the denitrification, a geochemical process that involves the conversion of nitrogen oxoanions and oxides into dinitrogen (N2[g]). Nars are complex enzymes with an (αβγ)2 biological assembly. The α- and β-subunits harbour the Mo-bisPGD cofactor and iron-sulphur clusters, while the integral membrane γ-subunit contains two b-type haems. The latter are involved in the oxidation of the membrane quinol pool and the generation of a proton gradient that energises the bacterium cell. In the present chapter, we update some general aspects of molybdo-enzymes and the present knowledge on Nars. Firstly, the special chemical properties that make Mo an efficient O-atom transfer catalyst are briefly presented. Next, the classification of molybdo-enzymes into different families based on the structural properties of the active site is discussed. Then, we review in detail the structural and spectroscopic properties of each subunit comprising the Nar heterotrimer, as well as the complex regulation of nar gene expression, the metabolic role of Nars within the bacterium cell and some key aspects of the catalytic mechanism.

Original languageEnglish
Title of host publicationMolybdenum and Tungsten Enzymes
Subtitle of host publicationBiochemistry
PublisherRoyal Society of Chemistry
Pages39-58
Number of pages20
Edition9
DOIs
Publication statusPublished - Jan 2017

Publication series

NameRSC Metallobiology
Number9
Volume2017-January
ISSN (Print)2045-547X

Fingerprint

Nitrate Reductases
Nitrate Reductase
Bacteria
Enzymes
Hydroquinones
Nitrogen Oxides
Membranes
Denitrification
Gene Expression Regulation
Ports and harbors
Heme
Sulfur
Gene expression
Microorganisms
Chemical properties
Transition metals
Protons
Structural properties
Catalytic Domain
Oxidoreductases

Cite this

Gonzalez, P. J., Rivas, M. G., & Moura, J. J. G. (2017). CHAPTER 3: Structure, Function and Mechanisms of Respiratory Nitrate Reductases. In Molybdenum and Tungsten Enzymes: Biochemistry (9 ed., pp. 39-58). (RSC Metallobiology; Vol. 2017-January, No. 9). Royal Society of Chemistry. https://doi.org/10.1039/9781782623762-00039
Gonzalez, Pablo J. ; Rivas, Maria G. ; Moura, José J.G. / CHAPTER 3 : Structure, Function and Mechanisms of Respiratory Nitrate Reductases. Molybdenum and Tungsten Enzymes: Biochemistry. 9. ed. Royal Society of Chemistry, 2017. pp. 39-58 (RSC Metallobiology; 9).
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Gonzalez, PJ, Rivas, MG & Moura, JJG 2017, CHAPTER 3: Structure, Function and Mechanisms of Respiratory Nitrate Reductases. in Molybdenum and Tungsten Enzymes: Biochemistry. 9 edn, RSC Metallobiology, no. 9, vol. 2017-January, Royal Society of Chemistry, pp. 39-58. https://doi.org/10.1039/9781782623762-00039

CHAPTER 3 : Structure, Function and Mechanisms of Respiratory Nitrate Reductases. / Gonzalez, Pablo J.; Rivas, Maria G.; Moura, José J.G.

Molybdenum and Tungsten Enzymes: Biochemistry. 9. ed. Royal Society of Chemistry, 2017. p. 39-58 (RSC Metallobiology; Vol. 2017-January, No. 9).

Research output: Chapter in Book/Report/Conference proceedingChapter

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Gonzalez PJ, Rivas MG, Moura JJG. CHAPTER 3: Structure, Function and Mechanisms of Respiratory Nitrate Reductases. In Molybdenum and Tungsten Enzymes: Biochemistry. 9 ed. Royal Society of Chemistry. 2017. p. 39-58. (RSC Metallobiology; 9). https://doi.org/10.1039/9781782623762-00039