The cytochromec reductase/oxidase respiratory pathway ofParacoccus denitrificans: Genetic and functional studies

Steinrücke, Peter; Gerhus, Ernst; Jetzek, Martin; Turba, Andreas; Ludwig, Bernd

doi:10.1007/bf00762219

Cited by 23 publications

(7 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…An early investigation using fetal rat liver concludes that apocytochrome c oxidase fails to accumulate in the absence of Ѩ-aminolevulinic acid, a precursor of all hemes (19). Similar observations have been made in Paracoccus denitrificans (20) and Saccharomyces cerevisiae (21) cox10 mutants. In the yeast mutants, subunit I is efficiently translated but is nearly absent in steady-state mitochondria (21).…”

supporting

confidence: 85%

“…The posttranslational loss of significant amounts of subunit I in yeast (21) could be due to in vivo degradation or, as indicated in the present study, could be explained by an in vitro instability during sample preparation or by structural alterations that reduce the ability of the epitope to be recognized by the antiserum. These explanations are also relevant to the report of a P. denitrificans strain with a deletion of the genes corresponding to coxII, cox10, and cox11 that does not express immunologically detectable subunit I (20). It is likely that modest overexpression of the gene for subunit I and isolation of the protein, as opposed to analysis in the membrane, significantly enhanced our ability to detect aposubunit I in this study.…”

Section: Discussionmentioning

confidence: 68%

See 1 more Smart Citation

Heme A Is Not Essential for Assembly of the Subunits of Cytochrome c Oxidase of Rhodobacter sphaeroides

Hiser

Hosler

2001

Journal of Biological Chemistry

View full text Add to dashboard Cite

The aa 3 -type cytochrome c oxidase of Rhodobacter sphaeroides, a proteobacterium of the ␣ subgroup, is structurally similar to the core subunits of the terminal oxidase in the mitochondrial electron transport chain. Subunit I, the product of the coxI gene, normally binds two heme A molecules. A deletion of cox10, the gene for the farnesyltransferase required for heme A synthesis, did not prevent high level accumulation of subunit I in the cytoplasmic membrane. Thus, subunit I can be expressed and stably inserted into the cytoplasmic membrane in the absence of heme A. Aposubunit I was purified via affinity chromatography to a polyhistidine tag. Copurification of subunits II and III with aposubunit I indicated that assembly of the core oxidase complex occurred without the binding of heme A. In addition to formation of the apooxidase containing all three large structural proteins, CoxI-II and CoxI-III heterodimers were isolated from cox10 deletion strains harboring expression plasmids with coxI and coxII or with coxI and coxIII, respectively. This demonstrated that subunit assembly of the apoenzyme was not an inherently ordered or sequential process. Thus, multiple paths must be considered for understanding the assembly of this integral membrane metalloprotein complex.

show abstract

supporting

confidence: 85%

Section: Discussionmentioning

confidence: 68%

Heme A Is Not Essential for Assembly of the Subunits of Cytochrome c Oxidase of Rhodobacter sphaeroides

Hiser

Hosler

2001

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

“…Apart from the well-characterized periplasmic cyt c550 a membrane bound c552 protein has been described [17]. This cytochrome has been shown to mediate electron-transfer from cytochrome c I to the aa 3oxidase, when c550 is virtually absent [39][40][41]64]. The 20-kDa protein has been purified to homogeneity, its gene cycM has been cloned, is presently sequenced, and mutant strains will soon be available (A. Turba, unpublished).…”

Section: Cytochrome C552mentioning

confidence: 99%

Genetics of Paracoccus denitrificans

Steinrücke

Ludwig

1993

FEMS Microbiology Letters

View full text Add to dashboard Cite

Paracoccus has approx. 15 subunits [28]. The transcriptional organization of this NDH-l-cluster is presently unknown. NQ01 and NQ02 code for flavoproteins, NQ03 to NQ06 are genes for iron-sulfur proteins whereas NQ07 to NQ014 code for polypeptides of the hydrophobic protein fraction [28]. The gene order in this cluster is NQ07, NQ06, NQ05, NQ04, NO02, NQ01 NQ03, NQ08 NQ09, NQ010, NQ011, NQO12, NQ013, and NQ014.Upstream of NQ07 an open reading frame with homology to Escherichia coli uvrA is found. A reading frame with homology to E. coli biotin acetyl-CoA carboxylase ligase has been found downstream of the cluster [28].Sequences for two genes, NQ01 [29], encoding the NADH-binding subunit, and NQ02 [30], which codes for an iron-sulfur protein, have been published. Two URFs have been found; sequence similarities of URF2 to ctaG of the Paracoccus cta-operon suggest a possible role as an assembly protein, most probably in the attachment of iron [29,30,55]. Because of its simpler structure the Paracoccus complex is likely to play an important part in investigating inhibitory agents or the mode of complex formation during assembly. Mutant strains are presently not available.

show abstract

“…Minagawa et al (13) reported the absence of the Escherichia coli cyoABCD gene products when only one of the subunit genes was deleted. Studies on assembly of the Paracoccus denitrificans aa 3 -type oxidase revealed that subunit I was not present in a subunit II gene deletion mutant, whereas subunit III was not absolutely essential for the formation of a subunit I⅐II subcomplex (14,15). Using the B. japonicum cbb 3 -type oxidase system as an example, we attempted to elucidate the role of its individual subunits in assembly and biological function.…”

mentioning

confidence: 99%

Assembly and Function of the Cytochrome cbb Oxidase Subunits in Bradyrhizobium japonicum

Zufferey

Preisig²,

Hennecke

et al. 1996

Journal of Biological Chemistry

103

115

View full text Add to dashboard Cite

The Bradyrhizobium japonicum cbb 3 -type cytochrome oxidase, which supports microaerobic respiration, is a multisubunit enzyme encoded by the genes of the fix-NOQP operon. We investigated the contribution of the individual subunits to function and assembly of the membrane-bound complex. In-frame deletion mutants of fixN, fixO, and fixQ, and an insertion mutant of fixP were constructed. All mutants, except the fixQ mutant, showed clearly altered absorption difference spectra of their membranes and decreased oxidase activities, and they were unable to fix nitrogen symbiotically. The presence of the individual subunits was assayed by Western blot analysis, using subunit-specific antibodies, and by heme staining of the c-type cytochromes FixO and FixP. These analyses led to the following conclusions: (i) FixN and FixO are necessary for assembly of the multimeric oxidase, (ii) FixN and FixO assemble independently of FixP, and (iii) FixQ is not required for complex formation and, therefore, does not seem to be an essential subunit. The possible oxidase biogenesis pathway involves the formation of a primary core complex consisting of FixN and FixO, which allows the subsequent association with FixP to form the complete enzyme.

show abstract

The cytochromec reductase/oxidase respiratory pathway ofParacoccus denitrificans: Genetic and functional studies

Cited by 23 publications

References 31 publications

Heme A Is Not Essential for Assembly of the Subunits of Cytochrome c Oxidase of Rhodobacter sphaeroides

Heme A Is Not Essential for Assembly of the Subunits of Cytochrome c Oxidase of Rhodobacter sphaeroides

Genetics of Paracoccus denitrificans

Assembly and Function of the Cytochrome cbb Oxidase Subunits in Bradyrhizobium japonicum

Contact Info

Product

Resources

About