Identification and Location of ε-N-Trimethyllysine in Yeast Cytochromes c

Abstract

Iso-1 cytochrome c of Soccharomyces cerevisiae contains 1 residue of e-N-trimethyllysine at position 72 in the sequence.Iso-11 cptochrome c-from this species and cytochrome c from Candida krusei also contain 1 residue of this amino acid.Thus, cytochromes c of Ascomycefes contain 1 residue and, as previously reported, a higher plant contains 2 residues of c-Wtrimethyllysine.This amino acid is completely absent from a large variety of animal cytochromes and from other types of proteins.In an earlier publication (I), we reported that Neurosporu cytochrome c and wheat germ cytochrome c contain 1 and 2 residues of e-N-trimethyllysine, respectively.The locations of this unusual amino acid in the amino acid sequences of these proteins were also identified.Further, it was noted (1) that e-N-trimethyllysine was absent from cytochromes c of various animal species previously studied in this laboratory.In order to determine further the distribution and significance of e-N-trimethyllysine we now wish to report studies on a variety of additional cytochromes c and on several other proteins. EXPERIMEKTAL PROCEDURES MaterialsSaccharomyces ceretisiae (baker's yeast) iso-and iso-cytochromes c, as well as those from Pacific lamprey, Sumia cynthiu (a moth), bullfrog, snapping turtle, and turkey, and alfalfa ferredoxin, were all generous gifts from Dr. Emanuel Margoliash.Can&da krusei cytochrome c was purchased from the Sankyo Company, Ltd., Tokyo, Japan.Subtilisin Carlsberg