THE BASIDIOMYCETE LENTINUS-EDODES LINEAR MITOCHONDRIAL-DNA PLASMID CONTAINS A SEGMENT EXHIBITING A HIGH AUTONOMOUSLY REPLICATING SEQUENCE ACTIVITY IN SACCHAROMYCES CEREVISIAE

A linear DNA plasmid, designated pLLE1, has been isolated from a mitochondrial fraction of a strain of Lentinus edodes. pLLE1 (11.0 kbp) was sensitive to the 3′-5′-acting exonuclease III and resistant to the 5′-3′-acting λ exonuclease. It showed no homology with mitochondrial and nuclear genomic DNAs of plasmidless strain as well as the pLLE1 -harboring host strain of L. edodes. The 1434-bp fragment (sequences) capable of autonomous replication in the yeast Saccharomyces cerevislae (ARS8) was cloned from pLLE1 DNA with Ylp32 (pBR322 containing yeast LEU2 DNA), which displayed a high ARS activity. The cloned 1434-bp fragment was shown to lie near to the end of pLLE1 DNA (nucleotides about 800-2200) and contained three consecutive ARS consensus sequences (A/T)TTTAT(A/G)TTT(A/T) of S. cerevisiae and dispersive eight ARS consensus-like sequences. The subcloned 366-bp fragment containing the three ARSs retained original ARS activity of the 1434-bp fragment. © 1990 Oxford University Press.