title: Replacement of cysteine-107 of Saccharomyces cerevisiae iso-1-cytochrome c with threonine: improved stability of the mutant protein.
abstract: Site-directed mutagenesis has been used to change the codon for cysteine-107 of Saccharomyces cerevisiae iso-1-cytochrome c to a threonine codon. The resulting protein is active in vivo, is methylated as in the wild-type protein and has optical properties indistinguishable from those of the wild-type protein. The threonine-107 iso-1-cytochrome c demonstrated fully reversible electrochemical behaviour and a mid-point reduction potential of 272 mV versus NHE. In addition, this mutant does not demonstrate a tendency to autoreduce or to dimerize as does the wild-type protein. These properties of the threonine-107 mutant establish that it will provide a useful background in which to make subsequent mutations for mechanistic and physical studies of yeast iso-1-cytochrome c.
authors.affiliation: Department of Biochemistry, University of British Columbia, Vancouver, Canada.
authors.forename: R L
authors.initials: RL
authors.lastname: Cutler
authors.forename: G J
authors.initials: GJ
authors.lastname: Pielak
authors.forename: A G
authors.initials: AG
authors.lastname: Mauk
authors.forename: M
authors.initials: M
authors.lastname: Smith
mesh_terms: D000595:Amino Acid Sequence; D003574:Cytochrome c Group / Q000235:genetics*; D045304:Cytochromes c; D004563:Electrochemistry; D008969:Molecular Sequence Data; D009154:Mutation; D015202:Protein Engineering; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins
chemical_list: C014059:CYC1 protein, S cerevisiae; D003574:Cytochrome c Group; D029701:Saccharomyces cerevisiae Proteins; D045304:Cytochromes c