CtaG is required for formation of active cytochrome C oxidase in Bacillus subtilis
Författare
Summary, in English
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.
Avdelning/ar
Publiceringsår
2004
Språk
Engelska
Sidor
415-425
Publikation/Tidskrift/Serie
Microbiology
Volym
150
Dokumenttyp
Artikel i tidskrift
Förlag
MAIK Nauka/Interperiodica
Ämne
- Biochemistry and Molecular Biology
- Microbiology
Nyckelord
- TMPD
- N,N,N′N′-tetramethyl-p-phenylenediamine
- ICP-MS
- inductively coupled plasma emission mass spectroscopy
Status
Published
Forskningsgrupp
- Microbiology Group
ISBN/ISSN/Övrigt
- ISSN: 1465-2080