Roles of the ccoGHIS gene products in the biogenesis of the cbb(3)-type cytochrome c oxidase.
In many bacteria the ccoGHIS cluster, located immediately downstream of the structural genes (ccoNOQP) of cytochrome cbb(3) oxidase, is required for the biogenesis of this enzyme. Genetic analysis of ccoGHIS in Rhodobacter capsulatus demonstrated that ccoG, ccoH, ccoI and ccoS are expressed independently of each other, and do not form a simple operon. Absence of CcoG, which has putative (4Fe-4S) cluster binding motifs, does not significantly affect cytochrome cbb(3) oxidase activity. However, CcoH and CcoI are required for normal steady-state amounts of the enzyme. CcoI is highly homologous to ATP-dependent metal ion transporters, and appears to be involved in the acquisition of copper for cytochrome cbb(3) oxidase, since a CcoI-minus phenotype could be mimicked by copper ion starvation of a wild-type strain. Remarkably, the small protein CcoS, with a putative single transmembrane span, is essential for the incorporation of the redox-active prosthetic groups (heme b, heme b(3 )and Cu) into the cytochrome cbb(3) oxidase. Thus, the ccoGHIS products are involved in several steps during the maturation of the cytochrome cbb(3) oxidase.
Koch
H G
HG
Department of Biology, Plant Science Institute, University of Pennsylvania, Philadelphia, PA 19104-6018, USA.
Winterstein
C
C
Saribas
A S
AS
Alben
J O
JO
Daldal
F
F
D020130:Bacterial Chromatophores / Q000201:enzymology / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D003300:Copper / Q000378:metabolism; D003576:Electron Transport Complex IV / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004795:Enzyme Stability; D015870:Gene Expression / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics; D005798:Genes, Bacterial / Q000235:genetics / Q000502:physiology*; D017930:Genes, Reporter / Q000235:genetics; D005816:Genetic Complementation Test; D006418:Heme / Q000378:metabolism; D007506:Iron-Sulfur Proteins / Q000235:genetics / Q000378:metabolism; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D009876:Operon / Q000235:genetics; D010084:Oxidation-Reduction; D010641:Phenotype; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D016354:Rhodobacter capsulatus / Q000166:cytology / Q000201:enzymology* / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000235:genetics
D001426:Bacterial Proteins; D007506:Iron-Sulfur Proteins; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D006418:Heme; D003300:Copper; D003576:Electron Transport Complex IV