Plasmid factors involved in the stable propagation of pKD1-derived vectors in Kluyveromyces lactis transformants have been identified. Three genes (A, B and C) have been found to be present in pKD1: the interruption of the B and C genes led to high plasmid instability. Stability could be restored in trans when host cells contained pKD1 as the resident plasmid (pKD1+ strains). The A gene, which codes for a site-specific recombinase, did not affect plasmid partitioning. Vectors bearing only the pKD1 replication origin (or a chromosomal ARS), and no other pKD1 sequence, were very unstable both in the presence and absence of the resident plasmid in host cells. These vectors could be stabilized in pKD1+ strains, but not in pKDI- strains, by the insertion of a 200 bp-long pKDI sequence. This sequence, called the cis-acting stability locus (CSL), together with the products of the B and C genes, ensured plasmid partitioning at cell divison. Possible hairpin structures and direct repeats were regularly spaced within the CSL. This region, and the corresponding cis-acting stabilizing elements of other yeast plasmids, did not have sequence homology but shared some structural regularities.
PLASMID FUNCTIONS INVOLVED IN THE STABLE PROPAGATION OF THE PKD1 CIRCULAR PLASMID IN KLUYVEROMYCES-LACTIS / Bianchi, Michele Maria; Santarelli, Roberta; Frontali, Laura. - In: CURRENT GENETICS. - ISSN 0172-8083. - 19:(1991), pp. 155-161. [10.1007/BF00336481]
PLASMID FUNCTIONS INVOLVED IN THE STABLE PROPAGATION OF THE PKD1 CIRCULAR PLASMID IN KLUYVEROMYCES-LACTIS
BIANCHI, Michele Maria;SANTARELLI, Roberta;FRONTALI, Laura
1991
Abstract
Plasmid factors involved in the stable propagation of pKD1-derived vectors in Kluyveromyces lactis transformants have been identified. Three genes (A, B and C) have been found to be present in pKD1: the interruption of the B and C genes led to high plasmid instability. Stability could be restored in trans when host cells contained pKD1 as the resident plasmid (pKD1+ strains). The A gene, which codes for a site-specific recombinase, did not affect plasmid partitioning. Vectors bearing only the pKD1 replication origin (or a chromosomal ARS), and no other pKD1 sequence, were very unstable both in the presence and absence of the resident plasmid in host cells. These vectors could be stabilized in pKD1+ strains, but not in pKDI- strains, by the insertion of a 200 bp-long pKDI sequence. This sequence, called the cis-acting stability locus (CSL), together with the products of the B and C genes, ensured plasmid partitioning at cell divison. Possible hairpin structures and direct repeats were regularly spaced within the CSL. This region, and the corresponding cis-acting stabilizing elements of other yeast plasmids, did not have sequence homology but shared some structural regularities.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.