Open AccessProtein complex formation during denitrification by Pseudomonas aeruginosa
Author(s) -
Borrerode Acuña José Manuel,
Timmis Kenneth N.,
Jahn Martina,
Jahn Dieter
Publication year - 2017
Publication title -
microbial biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.287
H-Index - 74
ISSN - 1751-7915
DOI - 10.1111/1751-7915.12851
Subject(s) - nitrite reductase , nitrate reductase , periplasmic space , denitrification , biochemistry , electron transport chain , reductase , chemistry , atp synthase , nitrite , cofactor , nitrate , anaerobic respiration , enzyme , biology , escherichia coli , bacteria , nitrogen , gene , organic chemistry , genetics
Summary The most efficient means of generating cellular energy is through aerobic respiration. Under anaerobic conditions, several prokaryotes can replace oxygen by nitrate as final electron acceptor. During denitrification, nitrate is reduced via nitrite, NO and N 2 O to molecular nitrogen (N 2 ) by four membrane‐localized reductases with the simultaneous formation of an ion gradient for ATP synthesis. These four multisubunit enzyme complexes are coupled in four electron transport chains to electron donating primary dehydrogenases and intermediate electron transfer proteins. Many components require membrane transport and insertion, complex assembly and cofactor incorporation. All these processes are mediated by fine‐tuned stable and transient protein–protein interactions. Recently, an interactomic approach was used to determine the exact protein–protein interactions involved in the assembly of the denitrification apparatus of Pseudomonas aeruginosa . Both subunits of the NO reductase Nor BC , combined with the flavoprotein NosR, serve as a membrane‐localized assembly platform for the attachment of the nitrate reductase Nar GHI , the periplasmic nitrite reductase NirS via its maturation factor NirF and the N 2 O reductase NosZ through NosR. A nitrate transporter (NarK2), the corresponding regulatory system Nar XL , various nitrite (Nir EJMNQ ) and N 2 O reductase (Nos FL ) maturation proteins are also part of the complex. Primary dehydrogenases, ATP synthase, most enzymes of the TCA cycle, and the SEC protein export system, as well as a number of other proteins, were found to interact with the denitrification complex. Finally, a protein complex composed of the flagella protein FliC, nitrite reductase NirS and the chaperone DnaK required for flagella formation was found in the periplasm of P. aeruginosa . This work demonstrated that the interactomic approach allows for the identification and characterization of stable and transient protein–protein complexes and interactions involved in the assembly and function of multi‐enzyme complexes.