The cycl-11 mutation in yeast reverts by recombination with a nonallelic gene: composite genes determining the iso-cytochromes c

Journal Article · Thu Oct 01 04:00:00 EDT 1981 · Proc. Natl. Acad. Sci. U.S.A.; (United States)

DOI:https://doi.org/10.1073/pnas.78.10.6334· OSTI ID:5443305

Ernst, J F ^[1]; Stewart, J W; Sherman, F

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1. Univ. of Rochester, NY

DNA sequence analysis of a cloned fragment directly established that the cycl-11 mutation of iso-l-cytochrome c in the yeast Saccharomyces cerevisiae is a two-base-pair substitution that changes the CCA proline codon at amino acid position 76 to a UAA nonsense codon. Analysis of 11 revertant proteins and one cloned revertant gene showed that reversion of the cycl-11 mutation can occur in three ways: a single base-pair substitution, which produces a serine replacement at position 76; recombination with the nonallelic CYC7 gene of iso-2-cytochrome c, which causes replacement of a segment in the cycl-11 gene by the corresponding segment of the CYC7 gene; and either a two-base-pair substitution or recombination with the CYC7 gene, which causes the formation of the normal iso-l-cytochrome c sequence. These results demonstrate the occurrence of low frequencies of recombination between nonallelic genes having extensive but not complete homology. The formation of composite genes that share sequences from nonallelic genes may be an evolutionary mechanism for producing protein diversities and for maintaining identical sequences at different loci.

• DOE Contract Number: AC02-76EV03490
• OSTI ID: 5443305
• Journal Information: Proc. Natl. Acad. Sci. U.S.A.; (United States), Journal Name: Proc. Natl. Acad. Sci. U.S.A.; (United States) Vol. 78:10; ISSN PNASA
• Country of Publication: United States
• Language: English

Related Subjects

550401* -- Genetics-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AUTORADIOGRAPHY
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
CODONS
CYTOCHROMES
DAYS LIVING RADIOISOTOPES
DNA
FUNGI
GENE MUTATIONS
GENE RECOMBINATION
GENETIC EFFECTS
ISOTOPES
LIGHT NUCLEI
MICROORGANISMS
MUTANTS
MUTATIONS
NUCLEI
NUCLEIC ACIDS
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PHOSPHORUS 32
PHOSPHORUS ISOTOPES
PIGMENTS
PLANTS
RADIOISOTOPES
REVERTANTS
SACCHAROMYCES
SACCHAROMYCES CEREVISIAE
YEASTS