Replacements of lysine 32 in yeast cytochrome c

Lysine 32 has been previously implicated by chemical modification and modeling studies as a key component of the domain which controls recognition and binding of cytochrome c to its physiological partners, e.g. cytochrome b sub(2), cytochrome c peroxidase, and cytochrome oxidase. In order to quantitate the importance of this residue, the authors have investigated the role of Lys-32 in the reactivity of cytochrome c in redox reactions in vitro and in vivo with protein partners by using a series of altered forms of iso-1-cytochrome c from the yeast Saccharomyces cerevisiae) in which Lys-32 is replaced by Leu-32, Gln-32, Trp-32, and Tyr-32.