CtaG is required for formation of active cytochrome C oxidase in Bacillus subtilis

Jenny Bengtsson, Claes von Wachenfeldt, Lena Winstedt, Per Nygaard, Lars Hederstedt

Research output: Contribution to journalArticlepeer-review


The Gram-positive bacterium Bacillus subtilis contains two respiratory oxidases of the haem-copper superfamily: cytochrome aa(3), which is a quinol oxidase, and cytochrome caa(3), which is a cytochrome c oxidase. Cytochrome c oxidase uniquely contains a di-copper centre, Cu-A. B. subtilis CtaG is a membrane protein encoded by the same gene cluster as that which encodes the subunits of cytochrome c oxidase. The role of B. subtilis CrtaG and orthologous proteins present in many other Gram-positive bacteria has remained unexplored. The sequence of CtaG is unrelated to that of CtaG/Cox11p, of proteobacteria and eukaryotic cells. This study shows that B. subtilis CtaG is essential for the formation of active cytochrome caa(3) but is not required for assembly of the core subunits I and II with haem in the membrane and it has no role in the synthesis of active cytochrome aa(3). B. subtilis YpmQ, a homologue to Sco1p of eukaryotic cells, is also a membrane-bound cytochrome c oxidase-specific assembly factor. Properties of CtaG- and YpmQ-deficient mutants were compared. Cells lacking YpmQ showed a low cytochrome c oxidase activity and this defect was suppressed by the supplementation of the growth medium with copper ions. It has previously been proposed that YpmQ/Sco1p is involved in synthesis of the Cu-A centre. The results of this study are consistent with this proposal but the exact role of YpmQ in assembly of cytochrome c oxidase remains to be elucidated.
Original languageEnglish
Pages (from-to)415-425
Publication statusPublished - 2004

Subject classification (UKÄ)

  • Biochemistry and Molecular Biology
  • Microbiology

Free keywords

  • TMPD
  • N,N,N′N′-tetramethyl-p-phenylenediamine
  • ICP-MS
  • inductively coupled plasma emission mass spectroscopy


Dive into the research topics of 'CtaG is required for formation of active cytochrome C oxidase in Bacillus subtilis'. Together they form a unique fingerprint.

Cite this