Sequence diversity of yeast 2 microns RAF gene and its co-evolution with STB and REP1.
Despite the extensive study of yeast 2 microns plasmid, the exact function of plasmid-encoded RAF gene is not clear. Variants of 2 microns plasmids from industrial Saccharomyces cerevisiae yeasts were isolated and characterized. Sequencing of RAF alleles revealed about 8% nucleotide and 10% amino acid diversities between 2 microns variants of closely related strains, RAF sequence variations were correlated with STB-REP1 sequence diversity. We also used restriction fragment length polymorphism linkage to screen a large number of yeast strains from different fermentation industries. The results clearly show a tight linkage of STB-REP1-RAF variations. Thus, our observations suggest that plasmid-borne cis- and trans-acting elements co-evolved to form an optimal molecular parasite and that RAF may play a role in active plasmid partitioning.
Department of Biology, University of Saskatchewan, Saskatoon, Canada.
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D000483:Alleles; D000595:Amino Acid Sequence; D001483:Base Sequence; D015139:Blotting, Southern; D003001:Cloning, Molecular; D005800:Genes, Fungal; D008040:Genetic Linkage; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics*; D012150:Polymorphism, Restriction Fragment Length; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000235:genetics*