A dedicated haem lyase is required for the maturation of a novel bacterial cytochrome c with unconventional covalent haem binding

Hartshorne, Robert S., Kern, Melanie, Meyer, Björn, Clarke, Thomas A. ORCID: https://orcid.org/0000-0002-6234-1914, Karas, Michael, Richardson, David J. ORCID: https://orcid.org/0000-0002-6847-1832 and Simon, Jörg (2007) A dedicated haem lyase is required for the maturation of a novel bacterial cytochrome c with unconventional covalent haem binding. Molecular Microbiology, 64 (4). pp. 1049-1060. ISSN 0950-382X

Preview

PDF (Hartshorne_MCCA.pdf) Download (425kB) | Preview

Abstract

In bacterial c-type cytochromes, the haem cofactor is covalently attached via two cysteine residues organized in a haem c-binding motif. Here, a novel octa-haem c protein, MccA, is described that contains only seven conventional haem c-binding motifs (CXXCH), in addition to several single cysteine residues and a conserved CH signature. Mass spectrometric analysis of purified MccA from Wolinella succinogenes suggests that two of the single cysteine residues are actually part of an unprecedented CX15CH sequence involved in haem c binding. Spectroscopic characterization of MccA identified an unusual high-potential haem c with a red-shifted absorption maximum, not unlike that of certain eukaryotic cytochromes c that exceptionally bind haem via only one thioether bridge. A haem lyase gene was found to be specifically required for the maturation of MccA in W. succinogenes. Equivalent haem lyase-encoding genes belonging to either the bacterial cytochrome c biogenesis system I or II are present in the vicinity of every known mccA gene suggesting a dedicated cytochrome c maturation pathway. The results necessitate reconsideration of computer-based prediction of putative haem c-binding motifs in bacterial proteomes.

Item Type:	Article
Faculty \ School:	Faculty of Science > School of Biological Sciences
UEA Research Groups:	Faculty of Science > Research Groups > Molecular Microbiology Faculty of Science > Research Groups > Organisms and the Environment Faculty of Science > Research Centres > Centre for Molecular and Structural Biochemistry Faculty of Science > Research Groups > Energy Materials Laboratory
Depositing User:	Users 2731 not found.
Date Deposited:	24 May 2011 09:55
Last Modified:	16 May 2023 00:41
URI:	https://ueaeprints.uea.ac.uk/id/eprint/31288
DOI:	10.1111/j.1365-2958.2007.05712.x

Downloads

Actions (login required)

View Item