ISSN:
1432-0983
Schlagwort(e):
Key words Cytochrome b
;
Mutants
;
Mitochondria
;
Saccharomyces cerevisiae
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Biologie
Notizen:
Abstract The nucleotide changes present in a group of five cytochrome b mit– mutants were analyzed at the sequence level. Two single-base changes were found: one (M10-152) generated a nonsense codon in the first exon while the other (M8-181) created a missense substitution in the second exon. The other mutants all have multiple (three) substitutions that either resulted in a missense mutation in a coding region (M17-162) or else changed nucleotides in the last intron of the gene, so blocking its excision (M6-200 and M8-53). The synthesis of mitochondrial polypeptides and the steady state concentration of the complex-III subunits were examined. The Rieske protein and the core-4 and core-5 subunits were much reduced in all mutants. Consequently the overall stability of complex III is very sensitive even to amino-acid substitutions in the cytochrome b protein. Mutant M8-53 provides direct evidence for the proposed role of the P9.1 stem in the core structure of the group-I type last intron of this gene.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/s002940050121
