Linked Life Data

8393450

Source:http://linkedlifedata.com/resource/pubmed/id/8393450

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
21
pubmed:dateCreated
1993-8-30
pubmed:abstractText
We characterized six novel missense mutations in mitochondrial cytochrome b (C133Y, W142R, S206L, M221K, L282F, and G340E) which impair the respiratory growth of yeast and which have differential effects on the functioning and assembly of the bc1 complex. The mutations have been mapped genetically in exons of the mitochondrial gene coding for apocytochrome b and their nucleotide sequence established. The mutants help to better define the topographical and primary sequence location of the ubiquinol oxidase (center P) and ubiquinone reductase (center N) sites on cytochrome b. Two mutants (C133Y and S206L) resulted in an active assembled complex, with selective disturbances of heme 565 and heme 562, respectively, which is consistent with the assignment of the axial ligands of these hemes; the C133Y mutation induced myxothiazol resistance, whereas the S206L did not modify the antimycin binding site, although perturbing the center N. These two amino acid replacements, along with those described elsewhere (Tron, T., and Lemesle-Meunier, D. (1990) Curr. Genet. 18, 413-419), constitute a novel class of mutants exhibiting appreciable electron transfer activity, despite their impaired ability to grow on respiratory substrates, raising the possibility that these mutants carry alleles which result in "decoupling" of proton translocation from electron transfer. Mutants W142R and M221K had an inactive but well assembled bc1 complex, whereas the G34OE and L282F mutations impaired the assembly of the bc1 complex.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
268
pubmed:geneSymbol
cob-box
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
15626-32
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Cytochrome b-deficient mutants of the ubiquinol-cytochrome c oxidoreductase in Saccharomyces cerevisiae. Consequence for the functional and structural characteristics of the complex.
pubmed:affiliation
Unité de Métabolisme Energétique-L.C.B-Boite, Marseille, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't