Deoxyribonucleic acid sequence organization of a yeast plasmid

Abstract

Two-micrometer DNA, a circular plasmid of Saccharomyces cerevisiae, contains 2 nontandem repeated sequences which are inverted with respect to one another. These repeated sequences together account for 21% of the molecule length. Restriction endonuclease analysis and EM demonstrated the existence of 2 forms of 2-.mu.m DNA differing in the orientation of the interstitial segments bounded by the inverted repeated sequences. The 2 forms of 2-.mu.m DNA could result from an intramolecular reciprocal recombination between inverted repeat elements. A map containing the restriction endonuclease sites and the units of the inverted repeat was constructed.