SEQUENCES OF SACCHAROMYCES-CEREVISIAE 2 MU-M DNA IMPROVING PLASMID PARTITIONING IN HANSENULA-POLYMORPHA

Insertion of the HindIII-PstI fragment of Saccharomyces cerevisiae 2 m u m DNA into the Hansenula polymorpha replicative plasmids decreases p lasmid copy number and ensures their distribution to daughter cells at both mitotic and meiotic cell divisions. This suggests that the stabi lization effect is caused by the improvement of plasmid partitioning. Deletion analysis revealed that the region of 2 mu m DNA sequence resp onsible for the increase of mitotic stability of H. polymorpha plasmid s involves the 2 mu m STB locus and adjoining region. Further analysis demonstrated that the stabilization effect may depend on the number o f 24-28 bp imperfect repeats which were found in several copies in the STB locus and adjoining region. (C) 1998 John Wiley & Sons, Ltd.