title: Isolation and characterization of pLS1 plasmid mutants with increased copy numbers.
abstract: Streptococcus pneumoniae genetic systems designed for isolation of plasmid mutants with copy-up phenotypes have been developed. The target plasmids have the pLS1 replicon, and two different strategies have been followed: (i) selection of clones exhibiting augmented resistance to antibiotics, or (ii) obligatory co-existence of incompatible plasmids. We have isolated 23 plasmid mutants exhibiting increased number of copies. All the mutations corresponded to four different alleles of the copG gene of plasmid pLS1. These strategies could be used with other plasmids.
authors.affiliation: Centro de Investigaciones Biológicas, CSIC, Madrid, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Acebo
authors.forename: M T
authors.initials: MT
authors.lastname: Alda
authors.forename: M
authors.initials: M
authors.lastname: Espinosa
authors.forename: G
authors.initials: G
authors.lastname: del Solar
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D018628:Gene Dosage; D005798:Genes, Bacterial / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D010957:Plasmids / Q000235:genetics*; D013296:Streptococcus pneumoniae / Q000235:genetics*