Comparative structural and functional analysis of two octaheme nitrite reductases from closely related Thioalkalivibrio species

Authors

  • Tamara Tikhonova,

    Corresponding author
    • Bach Institute of Biochemistry, Russian Academy of Sciences, Leninskii pr. 33, Moscow 119071, Russia
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  • Alexey Tikhonov,

    1. Bach Institute of Biochemistry, Russian Academy of Sciences, Leninskii pr. 33, Moscow 119071, Russia
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  • Anton Trofimov,

    Corresponding author
    1. Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, ul. Vavilova 32, Moscow 119991, Russia
    • Bach Institute of Biochemistry, Russian Academy of Sciences, Leninskii pr. 33, Moscow 119071, Russia
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  • Konstantin Polyakov,

    1. Bach Institute of Biochemistry, Russian Academy of Sciences, Leninskii pr. 33, Moscow 119071, Russia
    2. Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, ul. Vavilova 32, Moscow 119991, Russia
    3. National Research Centre ‘Kurchatov Institute’, Academic Kurchatov sq. 1, Moscow 123182, Russia
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  • Konstantin Boyko,

    1. Bach Institute of Biochemistry, Russian Academy of Sciences, Leninskii pr. 33, Moscow 119071, Russia
    2. National Research Centre ‘Kurchatov Institute’, Academic Kurchatov sq. 1, Moscow 123182, Russia
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  • Eugene Cherkashin,

    1. National Research Centre ‘Kurchatov Institute’, Academic Kurchatov sq. 1, Moscow 123182, Russia
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  • Tatiana Rakitina,

    1. National Research Centre ‘Kurchatov Institute’, Academic Kurchatov sq. 1, Moscow 123182, Russia
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  • Dmitry Sorokin,

    1. Winogradsky Institute of Microbiology, Russian Academy of Sciences, Leninskii pr. 32a, Moscow 119991, Russia
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  • Vladimir Popov

    1. Bach Institute of Biochemistry, Russian Academy of Sciences, Leninskii pr. 33, Moscow 119071, Russia
    2. National Research Centre ‘Kurchatov Institute’, Academic Kurchatov sq. 1, Moscow 123182, Russia
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Correspondence

T. Tikhonova, Bach Institute of Biochemistry, Russian Academy of Sciences, Leninskii pr. 33, Moscow 119071, Russia

Fax: +7 495 9542732

Tel: +7 495 9528799

E-mail: ttikhonova@inbi.ras.ru

A. Trofimov, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, ul. Vavilova 32, Moscow 119991, Russia

Fax: +7 499 1351405

Tel: +7 499 1359944

E-mail: burayatina@gmail.com

Abstract

Octaheme nitrite reductase from the haloalkaliphilic bacterium Thioalkalivibrio paradoxus was isolated and characterized. A comparative structural and functional analysis of two homologous octaheme nitrite reductases from closely related Thioalkalivibrio species was performed. It was shown that both enzymes have similar catalytic properties, owing to high structural similarity. Both enzymes are characterized by specific structural features distinguishing them from pentaheme cytochrome c nitrite reductases, such as the Tyr-Cys bond in the active site, the hexameric structure resulting in the formation of a void space inside the hexamer, and the product channel that opens into the void interior space of the hexamer. It is suggested that these specific structural features are responsible for the higher nitrite reductase activity, the greater preference for nitrite than for sulfite as a substrate, and the wider pH range of the catalytic activity of octaheme nitrite reductases than of pentaheme homologs.

Database

Nucleotide sequence data are available in the GenBank database under the accession number HQ665012.1. Structural data are available in the RCSB Protein Data Bank database under the accession numbers 3SXQ and 3TTB

Structured digital abstract

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