scholarly journals MUTANTS OF YEAST DEFECTIVE IN ISO-1-CYTOCHROME c

Genetics ◽  
1974 ◽  
Vol 77 (2) ◽  
pp. 255-284
Author(s):  
Fred Sherman ◽  
John W Stewart ◽  
Mary Jackson ◽  
Richard A Gilmore ◽  
John H Parker
Keyword(s):  
Cytochrome C ◽  
Deletion Mutant ◽  
Tertiary Structure ◽  
Complete Loss ◽  
X Ray ◽  
Cytochromes C ◽  
Lactate Medium ◽  
Resistant Mutants ◽  
Nonsense Suppressor ◽  
Incubation Temperatures

ABSTRACT A medium containing chlorolactate has been devised to enrich for mutants that are unable to utilize lactate for growth, and therefore that may be defective in cytochrome c. Complementation tests of 6,520 chlorolactate-resistant mutants that were obtained spontaneously or induced with UV, ICR-170, or nitrosoimidazolidone resulted in the identification of 195 mutations at the cycl locus, which controls the primary structure of iso-1-cytochrome c. These 195 mutants, with 16 cycl mutants previously isolated, were examined for total cytochrome c by spectroscopic methods, growth on lactate medium, suppressibility by defined nonsense suppressor, mutational sites by x-ray-induced recombination, ability to revert, and in 86 cases, whether intragenic revertants contain altered iso-1-cytochrome c. Except for the deletion mutant cycl-1, all of thb mutants appeared to contain single-site mutdons that could be assigned to at least 35 different sites within the gene. The cycl mutants either completely lacked iso-1-cytochrome c or contained iso-1-cytochromes c that were completely or partially nonfunctional. In spite of the fact that the cyd mutants obtained by the chlorolactate procedure were selected on the basis of defective function, 68% appeared to completely lack iso-1-cytochrome c. The remaining cycl mutants contained below normal amounts of iso-1-cytochromes c. Studies at several incubation temperatures indicated that these nonfunctional iso-1-cytochromes c were thermolabile. It is suggested that the predominant means for abolishing iso-1-cytochrome c by mutations are either through a complete loss, such as produced by chain terminating codons, or impairments through drastic changes of tertiary structure which lead to instability and thermolability.

scholarly journals A DELETION MAP OF cyc1 MUTANTS AND ITS CORRESPONDENCE TO MUTATIONALLY ALTERED ISO-1-CYTOCHROMES c OF YEAST

Genetics ◽  
1975 ◽  
Vol 81 (1) ◽  
pp. 51-73 ◽  
Author(s):  
Fred Sherman ◽  
Mary Jackson ◽  
Susan W Liebman ◽  
Ann Marie Schweingruber ◽  
John W Stewart
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Amino Acid ◽  
Cytochrome C ◽  
Primary Structure ◽  
Recombination Rates ◽  
Yeast Saccharomyces Cerevisiae ◽  
X Ray ◽  
Cytochromes C ◽  
Adjacent Point

ABSTRACT Mutants arising spontaneously from sporulated cultures of certain strains of yeast, Saccharomyces cerevisiae, contained deletions of the CYC1 gene which controls the primary structure of iso-1-cytochrome c. At least 60 different kinds of deletions were uncovered among the 104 deletions examined and these ranged in length from those encompassing only two adjacent point mutants to those encompassing at least the entire CYC1 gene. X-ray-induced recombination rates of crosses involving these deletions and cyc1 point mutants resulted in the assignment of 211 point mutants to 47 mutational sites and made it possible to unambiguously order 40 of these 47 sites. Except for one mutant, cyc1-15, there was a strict colinear relationship between the deletion map and the positions of 13 sites that were previously determined by amino acid alterations in iso-1-cytochromes c from intragenic revertants.

scholarly journals The conformation of eukaryotic cytochrome c around residues 39, 57, 59 and 74

1983 ◽  
Vol 213 (3) ◽  
pp. 687-700 ◽  
Author(s):  
M N Robinson ◽  
A P Boswell ◽  
Z X Huang ◽  
C G S Eley ◽  
G R Moore
Keyword(s):  
Cytochrome C ◽  
Redox State ◽  
Conformational Flexibility ◽  
Candida Krusei ◽  
Crystallographic Structure ◽  
Conformational Heterogeneity ◽  
X Ray ◽  
Cytochromes C ◽  
Similar Cluster ◽  
Horse Cytochrome

1H-n.m.r. studies of horse, tuna, Candida krusei and Saccharomyces cerevisiae cytochromes c showed that each of the proteins contains a similar cluster of residues at the bottom of the protein that assists in shielding the haem from the solvent. The relative positions of the residues forming these clusters vary continuously with temperature, and they change with the change in protein redox state. This conformational heterogeneity is discussed with reference to the conformational flexibility of cytochrome c around residues 57, 59 and 74. Spectroscopic measurements of pKa values for Lys-55 (horse and tuna cytochromes c) and His-33 and His-39 (C. krusei and S. cerevisiae cytochromes c) are in excellent agreement with expectations based on chemical-modification studies of horse cytochrome c. [Bosshard & Zürrer (1980) J. Biol. Chem. 255, 6694-6699] and on the X-ray-crystallographic structure of tuna cytochrome c [Takano & Dickerson (1981) J. Mol. Biol. 153, 79-94, 95-115].

scholarly journals Comparison of yeast and beef cytochrome c oxidases. Kinetics and binding of horse, fungal, and Euglena cytochromes c.

1979 ◽  
Vol 254 (23) ◽  
pp. 11973-11981 ◽  
Author(s):  
J.K. Dethmers ◽  
S. Ferguson-Miller ◽  
E. Margoliash
Keyword(s):  
Cytochrome C ◽  
Cytochromes C

scholarly journals Multiple low spin forms of the cytochrome c ferrihemochrome. EPR spectra of various eukaryotic and prokaryotic cytochromes c.

1977 ◽  
Vol 252 (2) ◽  
pp. 574-582 ◽  
Author(s):  
D L Brautigan ◽  
B A Feinberg ◽  
B M Hoffman ◽  
E Margoliash ◽  
J Preisach ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Epr Spectra ◽  
Cytochromes C

scholarly journals S11.25 X-ray structure of carbon monoxide at copper site of the dinuclear site of cytochrome c oxidase

2008 ◽  
Vol 1777 ◽  
pp. S71
Author(s):  
Kazumasa Muramoto ◽  
Naoki Nakagawa ◽  
Maki Taniguchi ◽  
Katsumasa Kanda ◽  
Kyoko Shinzawa-Itoh ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
X Ray ◽  
Copper Site

scholarly journals The amino acid sequence of cytochromes c-551 from three species of Pseudomonas

1973 ◽  
Vol 131 (3) ◽  
pp. 485-498 ◽  
Author(s):  
R. P. Ambler ◽  
Margaret Wynn
Keyword(s):  
Amino Acids ◽  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Cytochrome C ◽  
Amino Acid Sequence ◽  
Amino Acid Sequences ◽  
Mitochondrial Cytochrome ◽  
Cytochromes C ◽  
Lending Library ◽  
Single Peptide

The amino acid sequences of the cytochromes c-551 from three species of Pseudomonas have been determined. Each resembles the protein from Pseudomonas strain P6009 (now known to be Pseudomonas aeruginosa, not Pseudomonas fluorescens) in containing 82 amino acids in a single peptide chain, with a haem group covalently attached to cysteine residues 12 and 15. In all four sequences 43 residues are identical. Although by bacteriological criteria the organisms are closely related, the differences between pairs of sequences range from 22% to 39%. These values should be compared with the differences in the sequence of mitochondrial cytochrome c between mammals and amphibians (about 18%) or between mammals and insects (about 33%). Detailed evidence for the amino acid sequences of the proteins has been deposited as Supplementary Publication SUP 50015 at the National Lending Library for Science and Technology, Boston Spa, Yorks. LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1973), 131, 5.

Sulphide as an inhibitor and electron donor for the cytochrome c oxidase system

1982 ◽  
Vol 60 (6) ◽  
pp. 613-623 ◽  
Author(s):  
P. Nicholls ◽  
J.-K. Kim
Keyword(s):  
Cytochrome C ◽  
Oxygen Uptake ◽  
Cytochrome C Oxidase ◽  
Submitochondrial Particles ◽  
Inhibitory Interaction ◽  
Cytochromes C ◽  
Subsequent Step ◽  
Oxidase Enzyme ◽  
Rapid Reaction ◽  
The One

Anomalies both kinetic and equilibrium in nature are described for the inhibition of cytochrome c oxidase activity by sulphide in the isolated enzyme and in submitochondrial particles. These anomalies are related to the involvement of more than 1 mol of sulphide in the blockage of one cytochrome aa3 centre. Sulphide reduces resting cytochrome a3, a reaction that results in oxygen uptake and the loss of a sulphide molecule. Sulphide can also reduce cytochromes c and a; in the former case, a part of the one-equivalent oxidation product, presumed to be the SH∙ radical, reacts with oxygen. Such oxygen uptake is also seen under aerobic conditions when ferricyanide reacts with sulphide. Three phases are identified in the inhibitory interaction of sulphide with the cytochrome c oxidase enzyme itself: an initial rapid reaction involving sulphide oxidation, oxygen uptake, and conversion of cytochrome aa3 into the low-spin "oxyferri" form; a subsequent step in which sulphide reduces cytochrome a; and the final inhibitory step in which a third molecule of sulphide binds the a3 iron centre in the cytochrome [Formula: see text] (oxy) species to give cytochrome [Formula: see text]. The initial events parallel some of the events in the interaction of the cytochrome c – cytochrome aa3 system with monothiols; the final inhibitory event resembles that with cyanide.

scholarly journals Multiple light-induced reactions of cytochromes b and c in Rhodopseudomonas spheroides

1969 ◽  
Vol 114 (4) ◽  
pp. 793-799 ◽  
Author(s):  
O. T. G. Jones
Keyword(s):  
Cytochrome C ◽  
Cytochrome B ◽  
Photochemical Reaction ◽  
Room Temperature ◽  
Close Association ◽  
Antimycin A ◽  
Reaction Centre ◽  
Difference Spectra ◽  
Cytochromes C ◽  
Rhodopseudomonas Spheroides

Illumination of chromatophore preparations from Rhodopseudomonas spheroides causes the oxidation of a cytochrome c and a slight oxidation of a cytochrome b with a maximum at 560nm. When illuminated in the presence of antimycin A the oxidation of cytochrome c was more pronounced and cytochrome b560 was reduced; the dark oxidation of cytochrome b560 was biphasic in the presence of succinate, but not in the presence of NADH, a less effective reductant. Split-beam spectroscopy showed that, in addition to the reduction of cytochrome b560, another pigment with maxima at 565 and 537nm. was reduced and was more rapidly oxidized in the dark than cytochrome b560. This pigment, tentatively identified as cytochrome b565, was also detected in spectra at 77°k, after brief illumination at room temperature; the maxima at 77°k were at 562 and 536nm. In the absence of antimycin A, light caused a transient reduction of cytochrome b565 and an oxidation of cytochrome b560. Dark oxidation of b565 was rapid, even in the presence of antimycin A and succinate. Difference spectra, at 77°k, of ascorbate-reduced minus succinate-reduced chromatophores or of anaerobic succinate-reduced minus aerobic succinate-reduced chromatophores suggested that two cytochromes c were present, with maxima at 547 and 549nm. When chromatophores frozen at 77°k were illuminated both these cytochromes c were oxidized, indicating a close association with the photochemical reaction centre. A scheme involving two reaction centres is proposed to explain these results.

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