Literature summary for 7.1.1.8 extracted from

Kessl, J.J.; Ha, K.H.; Merritt, A.K.; Lange, B.B.; Hill, P.; Meunier, B.; Meshnick, S.R.; Trumpower, B.L.
Cytochrome b mutations that modify the ubiquinol-binding pocket of the cytochrome bc1 complex and confer anti-malarial drug resistance in Saccharomyces cerevisiae (2005), J. Biol. Chem., 280, 17142-17148.

Search for more literature for 7.1.1.8

Protein Variants

Protein Variants	Comment	Organism
F278I	site-directed mutagenesis, the mutation does not affect the residues of the EF helix of cytochrome b, the mutant shows similar ubiquinol-binding as the wild-type complex	Saccharomyces cerevisiae
I269M	site-directed mutagenesis, the mutation affects the residues of the EF helix of cytochrome b, the mutant shows modified ubiquinol-binding compared to the wild-type complex	Saccharomyces cerevisiae
L282V	site-directed mutagenesis, the mutation affects the residues of the EF helix of cytochrome b, the mutant shows modified ubiquinol-binding compared to the wild-type complex, the mutant is resistant to inhibition by atovaquone	Saccharomyces cerevisiae
additional information	cytochrome b mutations that modify the ubiquinol-binding pocket of the cytochrome bc1 complex and confer anti-malarial drug resistance in Saccharomyces cerevisiae, modeling the variations in cytochrome b structure and atovaquone binding with the mutated bc1 complexes, overview	Saccharomyces cerevisiae
Y279C	site-directed mutagenesis, the mutation affects the residues of the EF helix of cytochrome b, the mutant shows modified ubiquinol-binding compared to the wild-type complex, the mutant is resistant to inhibition by atovaquone	Saccharomyces cerevisiae
Y279S	site-directed mutagenesis, the mutation affects the residues of the EF helix of cytochrome b, the mutant shows modified ubiquinol-binding compared to the wild-type complex, the mutant is resistant to inhibition by atovaquone	Saccharomyces cerevisiae

Inhibitors

Inhibitors	Comment	Organism	Structure
atovaquone	an anti-malarial agent that specifically targets the cytochrome bc1 complex and inhibits parasite respiration in vivo, mutants Y279S, Y279C, and L282V are resistant to the inhibition, modeling the variations in cytochrome b structure and atovaquone binding with the mutated bc1 complexes	Saccharomyces cerevisiae

KM Value [mM]

KM Value [mM]	KM Value Maximum [mM]	Substrate	Comment	Organism	Structure
0.008	-	QH2	pH 7.0, 23°C, mutant I269M	Saccharomyces cerevisiae
0.013	-	QH2	pH 7.0, 23°C, wild-type enzyme and mutant F278I	Saccharomyces cerevisiae

Localization

Localization	Comment	Organism	GeneOntology No.	Textmining
mitochondrion	-	Saccharomyces cerevisiae	5739	-

Organism

Organism	UniProt	Comment	Textmining
Saccharomyces cerevisiae	-	-	-

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
ubiquinol-2 + 2 ferricytochrome c	ubiquinol binds to the specific binding pocket of the cytochrome bc1 complex	Saccharomyces cerevisiae	ubiquinone-2 + 2 ferrocytochrome c + 2 H+	-	?

Subunits

Subunits	Comment	Organism
More	modeling the variations in cytochrome b structure with the mutated bc1 complexes	Saccharomyces cerevisiae

Synonyms

Synonyms	Comment	Organism
cytochrome bc1 complex	-	Saccharomyces cerevisiae
ubiquinol-cytochrome c reductase	-	Saccharomyces cerevisiae

Temperature Optimum [°C]

Temperature Optimum [°C]	Temperature Optimum Maximum [°C]	Comment	Organism
23	-	assay at	Saccharomyces cerevisiae

Turnover Number [1/s]

Turnover Number Minimum [1/s]	Turnover Number Maximum [1/s]	Substrate	Comment	Organism	Structure
10	-	QH2	pH 7.0, 23°C, mutant Y279C	Saccharomyces cerevisiae
15	-	QH2	pH 7.0, 23°C, mutant L282V	Saccharomyces cerevisiae
20	-	QH2	pH 7.0, 23°C, mutant Y279S	Saccharomyces cerevisiae
30	-	QH2	pH 7.0, 23°C, mutant I269M	Saccharomyces cerevisiae
220	-	QH2	pH 7.0, 23°C, wild-type enzyme and mutant F278I	Saccharomyces cerevisiae

pH Optimum

pH Optimum Minimum	pH Optimum Maximum	Comment	Organism
7	-	assay at	Saccharomyces cerevisiae

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Release 2023.1 (January 2023)