Site-directedly mutated human cytochrome c which retains heme c via only one thioether bond.
Although Cys-14 (human numbering) of cytochrome c was conserved during its molecular evolution and it is supposed to be essential for most cytochromes c to retain heme c via two thioether bonds, a site-directedly mutated human cytochrome c which has an alanine residue at this position and only one thioether bond through Cys-17 turns out to be functional. This shows that Cys-14 is not essential. The absorption spectrum of the atypical cytochrome c is red shifted, and similar to those of Euglena and Crithidia cytochromes c, which also have only one thioether bond [Pettigrew, G.W., Leaver, J.L., Meyer, T.E., & Ryle, A.P. (1975) Biochem. J. 147, 291-302].
Tanaka
Y
Y
Institute for Fundamental Research, Research Center, Suntory Ltd., Osaka.
Kubota
I
I
Amachi
T
T
Yoshizumi
H
H
Matsubara
H
H
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D003574:Cytochrome c Group / Q000737:chemistry / Q000235:genetics*; D006418:Heme / Q000737:chemistry / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D015003:Yeasts / Q000201:enzymology / Q000235:genetics
D000596:Amino Acids; D003574:Cytochrome c Group; D006418:Heme