ISSN:
1432-0983
Keywords:
Kluyveromyces
;
Partitioning
;
pKD1
;
Transformation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary 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 pKD1o strains, by the insertion of a 200 pb-long pKD1 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.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00336481
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