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Cooperation between two periplasmic copper chaperones is required for full activity of the cbb 3 ‐type cytochrome c oxidase and copper homeostasis in Rhodobacter capsulatus
Author(s) -
Trasnea PetruIulian,
Utz Marcel,
KhalfaouiHassani Bahia,
Lagies Simon,
Daldal Fevzi,
Koch HansGeorg
Publication year - 2016
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/mmi.13321
Subject(s) - periplasmic space , rhodobacter , biology , cytochrome c oxidase , biochemistry , electron transport complex iv , cofactor , cytochrome , yeast , copper , enzyme , microbiology and biotechnology , mutant , chemistry , escherichia coli , gene , organic chemistry
Summary Copper (Cu) is an essential micronutrient that functions as a cofactor in several important enzymes, such as respiratory heme‐copper oxygen reductases. Yet, Cu is also toxic and therefore cells engage a highly coordinated Cu uptake and delivery system to prevent the accumulation of toxic Cu concentrations. In this study, we analyzed Cu delivery to the cbb 3 ‐type cytochrome c oxidase ( cbb 3 ‐Cox) of Rhodobacter capsulatus . We identified the PCu A C‐like periplasmic chaperone PccA and analyzed its contribution to cbb 3 ‐Cox assembly. Our data demonstrate that PccA is a Cu‐binding protein with a preference for Cu(I), which is required for efficient cbb 3 ‐Cox assembly, in particular, at low Cu concentrations. By using in vivo and in vitro cross‐linking, we show that PccA forms a complex with the Sco1‐homologue SenC. This complex is stabilized in the absence of the cbb 3 ‐Cox‐specific assembly factors CcoGHIS. In cells lacking SenC, the cytoplasmic Cu content is significantly increased, but the simultaneous absence of PccA prevents this Cu accumulation. These data demonstrate that the interplay between PccA and SenC not only is required for Cu delivery during cbb 3 ‐Cox assembly but also regulates Cu homeostasis in R. capsulatus .