期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1980
卷号：77
期号：1
页码：541-545
DOI：10.1073/pnas.77.1.541
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The two apocytochrome c proteins of yeast are coded for by separate genes. Iso-2-cytochrome c differs from the iso-1 protein at 17 positions within a homologous sequence of 108 amino acids. The previously cloned iso-1-cytochrome c coding sequence has been used to identify lambda-yeast recombinant phage containing the gene for iso-2-cytochrome c. The latter protein contains the dipeptide Ala-Ala which is coded for by the nucleic acid sequence G-C-N-G-C-N. The recognition specificity of restriction endonuclease Fnu4HI for G-C-N-G-C provided a rapid means of locating the region of the cloned fragment which codes for iso-2-cytochrome c. The DNA sequence of this gene has been determined and compared with that of the iso-1-cytochrome c locus. There is no intervening sequence within the gene for iso-2-cytochrome c. At 45 of the 91 positions for which iso-1- and iso-2-cytochrome c have the same amino acid, the codons differ. Such third position variation does not occur within the region coding for amino acids 70-80, the protein sequence that is also most conserved among all eukaryotic cytochromes c.
