The CcmC-CcmE interaction during cytochrome c maturation by System I is driven by protein-protein and not protein-heme contacts.

Details

Ressource 1Download: J. Biol. Chem.-2018-Shevket-16778-90.pdf (1729.12 [Ko])
State: Public
Version: Final published version
Serval ID
serval:BIB_438639CA1417
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
The CcmC-CcmE interaction during cytochrome c maturation by System I is driven by protein-protein and not protein-heme contacts.
Journal
The Journal of biological chemistry
Author(s)
Shevket S.H., Gonzalez D., Cartwright J.L., Kleanthous C., Ferguson S.J., Redfield C., Mavridou DAI
ISSN
1083-351X (Electronic)
ISSN-L
0021-9258
Publication state
Published
Issued date
26/10/2018
Peer-reviewed
Oui
Volume
293
Number
43
Pages
16778-16790
Language
english
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't
Publication Status: ppublish
Abstract
Cytochromes c are ubiquitous proteins, essential for life in most organisms. Their distinctive characteristic is the covalent attachment of heme to their polypeptide chain. This post-translational modification is performed by a dedicated protein system, which in many Gram-negative bacteria and plant mitochondria is a nine-protein apparatus (CcmA-I) called System I. Despite decades of study, mechanistic understanding of the protein-protein interactions in this highly complex maturation machinery is still lacking. Here, we focused on the interaction of CcmC, the protein that sources the heme cofactor, with CcmE, the pivotal component of System I responsible for the transfer of the heme to the apocytochrome. Using in silico analyses, we identified a putative interaction site between these two proteins (residues Asp <sup>47</sup> , Gln <sup>50</sup> , and Arg <sup>55</sup> on CcmC; Arg <sup>73</sup> , Asp <sup>101</sup> , and Glu <sup>105</sup> on CcmE), and we validated our findings by in vivo experiments in Escherichia coli Moreover, employing NMR spectroscopy, we examined whether a heme-binding site on CcmE contributes to this interaction and found that CcmC and CcmE associate via protein-protein rather than protein-heme contacts. The combination of in vivo site-directed mutagenesis studies and high-resolution structural techniques enabled us to determine at the residue level the mechanism for the formation of one of the key protein complexes for cytochrome c maturation by System I.
Keywords
Amino Acid Substitution, Apoproteins/chemistry, Apoproteins/genetics, Apoproteins/metabolism, Bacterial Outer Membrane Proteins/chemistry, Bacterial Outer Membrane Proteins/genetics, Bacterial Outer Membrane Proteins/metabolism, Binding Sites, Crystallography, X-Ray, Cytochromes c/chemistry, Cytochromes c/genetics, Cytochromes c/metabolism, Escherichia coli/genetics, Escherichia coli/growth & development, Escherichia coli/metabolism, Escherichia coli Proteins/chemistry, Escherichia coli Proteins/genetics, Escherichia coli Proteins/metabolism, Heme/chemistry, Heme/genetics, Heme/metabolism, Hemeproteins/chemistry, Hemeproteins/genetics, Hemeproteins/metabolism, Membrane Proteins/chemistry, Membrane Proteins/genetics, Membrane Proteins/metabolism, Mutagenesis, Site-Directed, Protein Conformation, Protein Interaction Domains and Motifs, CcmC, CcmE, Gram-negative bacteria, System I, cytochrome c, cytochrome c maturation, heme, nuclear magnetic resonance (NMR), post-translational modification (PTM), protein-protein interactions
Pubmed
Web of science
Open Access
Yes
Create date
26/09/2018 16:19
Last modification date
20/08/2019 14:47
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