[5] Ubiquinol-cytochrome-c oxidoreductase of Neurospora crassa

1995 ◽  
pp. 63-70 ◽  
Author(s):  
Ulrich Schulte ◽  
Hanns Weiss
Keyword(s):  
Cytochrome C ◽  
Neurospora Crassa

ISOLATION AND CLASSIFICATION OF EXTRANUCLEAR MUTANTS OF NEUROSPORA CRASSA

Genetics ◽  
1972 ◽  
Vol 71 (4) ◽  
pp. 521-533
Author(s):  
H Bertrand ◽  
T H Pittenger
Keyword(s):  
Cytochrome C ◽  
Neurospora Crassa ◽  
Slow Growth ◽  
Nuclear Factor ◽  
Group Iii ◽  
Group I ◽  
Growth Phenotype ◽  
Group Ii

ABSTRACT Four extranuclear mutants, [exn-1], [exn-2],[exn-4], and [stp-C], were obtained from N-methyl-N'-nitro-N-nitrosoguanidine-treated conidia and mycelium of Neurospora crassa. The three exn mutants grow with a pronounced lag from conidia and ascospores and are female fertile, whereas [stp-C] has a stop-start growth phenotype and is female sterile. The mitochondria from all four mutants are deficient in cytochromes a+a  3 and b, but contain an excess of cytochrome c. On the basis of growth and fertility, nuclear suppressors and complementation in heteroplasmons, 16 of the extranuclear mutants now available in Neurospora can be divided into three groups. Group I consists of 8 female-fertile variants with both poky-like growth and cytochrome defects. Their slow growth is suppressed by the nuclear factor, f, but not by a second nuclear suppressor, su-1([mi-3]). They complement with group III mutants in mixed cytoplasmons. Group II is represented by a single variant, [mi-3]. It is phenotypically modified by the su-1([mi-3]) factor, but not by f. Its unique cytochrome spectrum shows a deficiency of cytochrome a, but c and b are present. It complements in heteroplasmons with group I and III mutants. Group III included 7 female-sterile variants with stopper growth phenotypes and the same cytochrome defects as group I. Group III mutants complement both with group I and II isolates, but they are unaffected by either f or su-1.

scholarly journals Transient kinetic studies of Neurospora crassa cytochrome c oxidase

1983 ◽  
Vol 215 (2) ◽  
pp. 425-427 ◽  
Author(s):  
M Brunori ◽  
M C Silvestrini ◽  
M T Wilson ◽  
H Weiss
Keyword(s):  
Cytochrome C ◽  
Neurospora Crassa ◽  
Cytochrome C Oxidase ◽  
Flash Photolysis ◽  
Kinetic Studies ◽  
Dissociation Rate ◽  
Steady State Kinetic ◽  
Kinetic Investigations ◽  
Dissociation Rate Constants

The reaction of Neurospora crassa cytochrome c oxidase with CO was studied by flash-photolysis and rapid-mixing experiments, leading to the determination of the association and dissociation rate constants (7 X 10(4) M-1 X s-1 and 0.02s-1 respectively). Pre-steady-state kinetic investigations of the catalytic properties of the enzyme showed that under proper conditions Neurospora cytochrome c oxidase can be ‘pulsed’, i.e. activated, like the mammalian enzyme. The ‘pulsed’ species is spectroscopically different from the ‘resting’ one, and the decay into the ‘resting’ state is fast (t1/2 approx. 3 min).

Mutations in the structural gene for cytochrome c result in deficiency of both cytochromes aa 3 and c in Neurospora crassa

1994 ◽  
Vol 26 (4) ◽  
pp. 329-335 ◽  
Author(s):  
Drell A. Bottorff ◽  
Sukran Parmaksizoglu ◽  
Edmond G. Lemire ◽  
John W. Coffin ◽  
Helmut Bertrand ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Neurospora Crassa ◽  
Structural Gene
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