Nucleotide sequence involved in the replication of cloned yeast mitochondrial DNA

Abstract

A fragment of yeast mitochondrial DNA, Alu B, has two subfragments, Alu B1 and Alu B2. They were each cloned and sequenced. The autonomously replicating function of the curtailed Alu B1 (342 bp) was defined within 186 bp. A GC-rich sequence identical to the oris sequence in the curtailed Alu B1 was unnecessary for its autonomously replicating function. The 186 bp sequence had an ATATAAAT sequence and the stem and loop structures. The base sequence of Alu B2 also contained the same octanucleotides, the stem and loop structures, one oris sequence and one unique GC cluster. Yeast transformants with cloned Alu B2 grew slowly. The cloned Alu B2 was enlarged in the yeast host concomitantly with compensation of the slow growth of the transformants.