Identification and characterization of the novel subunit CcoM in the cbb₃-Cytochrome c oxidase from Pseudomonas stutzeri ZoBell

  • Cytochrome c oxidases (CcOs), members of the heme-copper containing oxidase (HCO) superfamily, are the terminal enzymes of aerobic respiratory chains. The cbb3-type cytochrome c oxidases (cbb3-CcO) form the C-family and have only the central catalytic subunit in common with the A- and B-family HCOs. In Pseudomonas stutzeri, two cbb3 operons are organized in a tandem repeat. The atomic structure of the first cbb3 isoform (Cbb3-1) was determined at 3.2 Å resolution in 2010 (S. Buschmann, E. Warkentin, H. Xie, J. D. Langer, U. Ermler, and H. Michel, Science 329:327-330, 2010, Unexpectedly, the electron density map of Cbb3-1 revealed the presence of an additional transmembrane helix (TMH) which could not be assigned to any known protein. We now identified this TMH as the previously uncharacterized protein PstZoBell_05036, using a customized matrix-assisted laser desorption ionization (MALDI)-tandem mass spectrometry setup. The amino acid sequence matches the electron density of the unassigned TMH. Consequently, the protein was renamed CcoM. In order to identify the function of this new subunit in the cbb3 complex, we generated and analyzed a CcoM knockout strain. The results of the biochemical and biophysical characterization indicate that CcoM may be involved in CcO complex assembly or stabilization. In addition, we found that CcoM plays a role in anaerobic respiration, as the ΔCcoM strain displayed altered growth rates under anaerobic denitrifying Pseudomonas stutzeri, a bacterium closely related to the human pathogen Pseudomonas aeruginosa.

Download full text files

Export metadata

Author:Martin Kohlstädt, Sabine Buschmann, Hao XieORCiDGND, Anja Resemann, Eberhard Warkentin, Julian David LangerORCiDGND, Hartmut MichelORCiDGND
Pubmed Id:
Parent Title (English):mBio
Publisher:American Society for Microbiology
Place of publication:Washington, DC
Document Type:Article
Date of Publication (online):2016/01/26
Date of first Publication:2016/01/26
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2016/10/17
Issue:1, Nr. e01921-15
Page Number:9
First Page:1
Last Page:9
Copyright © 2016 Kohlstaedt et al. This is an open-access article distributed under the terms of the Creative Commons Attribution-Noncommercial-ShareAlike 3.0 Unported license, which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original author and source are credited.
Institutes:Biochemie, Chemie und Pharmazie / Biochemie und Chemie
Angeschlossene und kooperierende Institutionen / MPI für Biophysik
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 57 Biowissenschaften; Biologie / 570 Biowissenschaften; Biologie
Licence (German):License LogoCreative Commons - Namensnennung-Keine kommerzielle Nutzung-Weitergabe unter gleichen Bedingungen