A water-lipid interface induces a highly dynamic folded state in apocytochrome c and cytochrome c, which may represent a common folding intermediate

Biochemistry ◽  
1992 ◽  
Vol 31 (6) ◽  
pp. 1636-1643 ◽  
Author(s):  
Harmen H. J. De Jongh ◽  
J. Antoinette Killian ◽  
Ben De Kruijff
Keyword(s):  
Cytochrome C ◽  
Folding Intermediate ◽  
Apocytochrome C

A noncovalent peptide complex as a model for an early folding intermediate of cytochrome c

Biochemistry ◽  
1993 ◽  
Vol 32 (38) ◽  
pp. 10271-10276 ◽  
Author(s):  
Lawren C. Wu ◽  
Paul B. Laub ◽  
Gulnur A. Elove ◽  
Jannette Carey ◽  
Heinrich Roder
Keyword(s):  
Cytochrome C ◽  
Folding Intermediate ◽  
Peptide Complex

scholarly journals CYC2 encodes a factor involved in mitochondrial import of yeast cytochrome c.

1993 ◽  
Vol 13 (10) ◽  
pp. 6442-6451 ◽  
Author(s):  
M E Dumont ◽  
J B Schlichter ◽  
T S Cardillo ◽  
M K Hayes ◽  
G Bethlendy ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Gene Product ◽  
Gene Dosage ◽  
Mitochondrial Protein ◽  
Yeast Saccharomyces Cerevisiae ◽  
Reading Frame ◽  
Transmembrane Segments ◽  
Apocytochrome C ◽  
Low Levels ◽  
Isogenic Strains

The gene CYC2 from the yeast Saccharomyces cerevisiae was previously shown to affect levels of mitochondrial cytochrome c by acting at a posttranslational step in cytochrome c biosynthesis. We report here the cloning and identification of the CYC2 gene product as a protein involved in import of cytochrome c into mitochondria. CYC2 encodes a 168-amino-acid open reading frame with at least two potential transmembrane segments. Antibodies against a synthetic peptide corresponding to the carboxyl terminus of the predicted sequence were raised. These antibodies recognize multiple bands on immunoblots of mitochondrial extracts. The intensities of these bands vary according to the gene dosage of CYC2 in various isogenic strains. Immunoblotting of subcellular fractions suggests that the CYC2 gene product is a mitochondrial protein. Deletion of CYC2 leads to accumulation of apocytochrome c in the cytoplasm. However, strains with deletions of this gene still import low levels of cytochrome c into mitochondria. The effects of cyc2 mutations are more pronounced in rho- strains than in rho+ strains, even though rho- strains that are CYC2+ contain normal levels of holocytochrome c. cyc2 mutations affect levels of iso-1-cytochrome c more than they do levels of iso-2-cytochrome c, apparently because of the greater susceptibility of apo-iso-1-cytochrome c to degradation in the cytoplasm. We propose that CYC2 encodes a factor that increases the efficiency of cytochrome c import into mitochondria.

scholarly journals In vitro reconstitution reveals major differences between human and bacterial cytochrome c synthases

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Molly C Sutherland ◽  
Deanna L Mendez ◽  
Shalon E Babbitt ◽  
Dustin E Tillman ◽  
Olga Melnikov ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Heme Proteins ◽  
Alpha Helix ◽  
Release Mechanism ◽  
Cytochrome C Biogenesis ◽  
Peptide Analogs ◽  
Apocytochrome C ◽  
In Vitro Reconstitution ◽  
Cytochromes C

Cytochromes c are ubiquitous heme proteins in mitochondria and bacteria, all possessing a CXXCH (CysXxxXxxCysHis) motif with covalently attached heme. We describe the first in vitro reconstitution of cytochrome c biogenesis using purified mitochondrial (HCCS) and bacterial (CcsBA) cytochrome c synthases. We employ apocytochrome c and peptide analogs containing CXXCH as substrates, examining recognition determinants, thioether attachment, and subsequent release and folding of cytochrome c. Peptide analogs reveal very different recognition requirements between HCCS and CcsBA. For HCCS, a minimal 16-mer peptide is required, comprised of CXXCH and adjacent alpha helix 1, yet neither thiol is critical for recognition. For bacterial CcsBA, both thiols and histidine are required, but not alpha helix 1. Heme attached peptide analogs are not released from the HCCS active site; thus, folding is important in the release mechanism. Peptide analogs behave as inhibitors of cytochrome c biogenesis, paving the way for targeted control.

scholarly journals Amide protection in an early folding intermediate of cytochrome c

1998 ◽  
Vol 3 (4) ◽  
pp. 293-301 ◽  
Author(s):  
J Michael Sauder ◽  
Heinrich Roder
Keyword(s):  
Cytochrome C ◽  
Folding Intermediate

Loading rat liver mitochondria with apocytochrome c provokes exit of cytochrome c

1988 ◽  
Vol 266 (2) ◽  
pp. 516-521 ◽  
Author(s):  
Vicente J. Miralles ◽  
Maria Jeśus Marcote ◽  
José Hernández-Yago ◽  
Santiago Grisoliá
Keyword(s):  
Cytochrome C ◽  
Rat Liver ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Apocytochrome C

scholarly journals Role of cytochrome c heme lyase in mitochondrial import and accumulation of cytochrome c in Saccharomyces cerevisiae.

1991 ◽  
Vol 11 (11) ◽  
pp. 5487-5496 ◽  
Author(s):  
M E Dumont ◽  
T S Cardillo ◽  
M K Hayes ◽  
F Sherman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cytochrome C ◽  
Mitochondrial Membrane ◽  
Intermembrane Space ◽  
Inner Mitochondrial Membrane ◽  
Yeast Saccharomyces Cerevisiae ◽  
Apocytochrome C ◽  
Cytochrome C Heme Lyase

Heme is covalently attached to cytochrome c by the enzyme cytochrome c heme lyase. To test whether heme attachment is required for import of cytochrome c into mitochondria in vivo, antibodies to cytochrome c have been used to assay the distributions of apo- and holocytochromes c in the cytoplasm and mitochondria from various strains of the yeast Saccharomyces cerevisiae. Strains lacking heme lyase accumulate apocytochrome c in the cytoplasm. Similar cytoplasmic accumulation is observed for an altered apocytochrome c in which serine residues were substituted for the two cysteine residues that normally serve as sites of heme attachment, even in the presence of normal levels of heme lyase. However, detectable amounts of this altered apocytochrome c are also found inside mitochondria. The level of internalized altered apocytochrome c is decreased in a strain that completely lacks heme lyase and is greatly increased in a strain that overexpresses heme lyase. Antibodies recognizing heme lyase were used to demonstrate that the enzyme is found on the outer surface of the inner mitochondrial membrane and is not enriched at sites of contact between the inner and outer mitochondrial membranes. These results suggest that apocytochrome c is transported across the outer mitochondrial membrane by a freely reversible process, binds to heme lyase in the intermembrane space, and is then trapped inside mitochondria by an irreversible conversion to holocytochrome c accompanied by folding to the native conformation. Altered apocytochrome c lacking the ability to have heme covalently attached accumulates in mitochondria only to the extent that it remains bound to heme lyase.

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