The role of various domains of the iron-sulfur protein in the assembly and activity of the cytochrome bc1 complex of yeast mitochondria

被引:7
作者
Beattie, DS [1 ]
Wang, YD [1 ]
Obungu, VH [1 ]
机构
[1] W Virginia Univ, Sch Med, Dept Biochem, Morgantown, WV 26506 USA
关键词
cytochrome bc(1) complex; complex III; iron-sulfur protein; yeast mitochondria; ubiquinol; cytochrome c reductase;
D O I
10.1023/A:1005415611822
中图分类号
Q6 [生物物理学];
学科分类号
071011 ;
摘要
Assembly studies in vitro of deletion mutants of the iron-sulfur protein into the cytochrome bc(1) complex revealed that mutants localized in the extramembranous regions of the protein were not assembled into the complex-in:contrast to the efficient assembly of mutants in the membrane-spanning region. Charged amino acids located in the extramembranous alpha 1-beta 4 loop and the alpha 1 helix were mutated and expressed in yeast cells lacking the gene for the iron-sulfur protein. Mutating the charged amino acid residues H124, E125, R146, K148, and D149 as well as V132 and W152 resulted in loss of enzymatic activity due to the loss of iron-sulfur protein suggesting that these amino acids are required to maintain protein stability. By contrast, no loss of iron-sulfur protein accompanied the 30-50% loss of bc(1) complex activity in mutants of three conserved alanine residues, A86, A90 and A92, suggesting that these residues may be involved in the proposed movement of,the flexible tether of the iron-sulfur protein during catalysis.
引用
收藏
页码:215 / 224
页数:10
相关论文
共 24 条
[1]  
BECKMANN JD, 1989, J BIOL CHEM, V264, P3713
[2]   The chemistry and mechanics of ubihydroquinone oxidation at center P (Qo) of the cytochrome bc1 complex [J].
Brandt, U .
BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS, 1998, 1365 (1-2) :261-268
[3]   THE PROTONMOTIVE Q-CYCLE IN MITOCHONDRIA AND BACTERIA [J].
BRANDT, U ;
TRUMPOWER, B .
CRITICAL REVIEWS IN BIOCHEMISTRY AND MOLECULAR BIOLOGY, 1994, 29 (03) :165-197
[4]  
CRIVELLONE MD, 1988, J BIOL CHEM, V263, P14323
[5]   Structure and function of the cytochrome bc1 complex of mitochondria and photosynthetic bacteria [J].
Crofts, AR ;
Berry, EA .
CURRENT OPINION IN STRUCTURAL BIOLOGY, 1998, 8 (04) :501-509
[6]  
FU W, 1991, J BIOL CHEM, V266, P16212
[7]  
FU W, 1990, J BIOL CHEM, V265, P16541
[8]   MUTATIONAL ANALYSIS OF ASSEMBLY AND FUNCTION OF THE IRON-SULFUR PROTEIN OF THE CYTOCHROME BC(1) COMPLEX IN SACCHAROMYCES-CEREVISIAE [J].
GRAHAM, LA ;
BRANDT, U ;
SARGENT, JS ;
TRUMPOWER, BL .
JOURNAL OF BIOENERGETICS AND BIOMEMBRANES, 1993, 25 (03) :245-257
[9]  
GRAHAM LA, 1991, J BIOL CHEM, V266, P22485
[10]   Complete structure of the 11-subunit bovine mitochondrial cytochrome bc1 complex [J].
Iwata, S ;
Lee, JW ;
Okada, K ;
Lee, JK ;
Iwata, M ;
Rasmussen, B ;
Link, TA ;
Ramaswamy, S ;
Jap, BK .
SCIENCE, 1998, 281 (5373) :64-71