title: Isolation and characterization of an autonomously replicating sequence from Ustilago maydis.
abstract: DNA fragments that function as autonomously replicating sequences (ARSs) have been isolated from Ustilago maydis. When inserted into an integrative transforming vector, the fragments increased the frequency of U. maydis transformation several-thousandfold. ARS-containing plasmids were transmitted in U. maydis as extrachromosomal elements through replication. They were maintained at a level of about 25 copies per cell but were mitotically unstable. One ARS characterized in detail, which we called UARS1, was localized to a 1.7-kilobase fragment. UARS1 contained a cluster of active sequences. This element could be reduced further into three separate subfragments, each of which retained ARS activity. The smallest one was 383 base pairs (bp) long. Although not active itself in yeast, this small fragment contained seven 8-bp direct repeats, two contiguous 30-bp direct repeats, and five 11-bp units in both orientations with sequences similar but not identical to the consensus sequence found to be crucial for ARS activity in Saccharomyces cerevisiae.
authors.affiliation: Interdivisional Program in Molecular Biology, Cornell University Medical College, New York, New York 10021.
authors.forename: T
authors.initials: T
authors.lastname: Tsukuda
authors.forename: S
authors.initials: S
authors.lastname: Carleton
authors.forename: S
authors.initials: S
authors.lastname: Fotheringham
authors.forename: W K
authors.initials: WK
authors.lastname: Holloman
mesh_terms: D001483:Base Sequence; D001487:Basidiomycota / Q000235:genetics*; D004261:DNA Replication; D004262:DNA Restriction Enzymes; D004271:DNA, Fungal / Q000235:genetics / Q000302:isolation & purification*; D004926:Escherichia coli / Q000235:genetics; D008969:Molecular Sequence Data; D009710:Nucleotide Mapping; D010957:Plasmids; D014170:Transformation, Genetic; D014588:Ustilago / Q000235:genetics*
chemical_list: D004271:DNA, Fungal; D004262:DNA Restriction Enzymes