Modulation of O-2 reduction in Saccharomyces cerevisiae mitochondria

• Respiratory supercomplex factor (Rcf) 1 is a membrane-bound protein that modulates the activity of cytochrome c oxidase (CytcO) in Saccharomycescerevisiae mitochondria. To investigate this regulatory mechanism, we studied the interactions of CytcO with potassium cyanide (KCN) upon removal of Rcf Delta. While the addition of KCN to the wild-type mitochondria results in a full reduction of heme a, with the rcf Delta mitochondria, a significant fraction remains oxidized. Upon addition of ascorbate in the presence of O-2 and KCN, the reduction level of hemes a and b was a factor of similar to 2 larger with the wild-type than with the rcf Delta mitochondria. These data indicate that turnover of CytcO was less blocked in rcf Delta than in the wild-type mitochondria, suggesting that Rcf Delta modulates the structure of the catalytic site.

Subject headings

NATURVETENSKAP  -- Biologi -- Biokemi och molekylärbiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Biochemistry and Molecular Biology (hsv//eng)

Keyword

cytochrome aa(3)

cytochrome c oxidase

electron transfer

membrane protein

respiratory supercomplex factor

Saccharomy cescerevisiae

Biochemistry

biokemi

Publication and Content Type

ref (subject category)

art (subject category)