title: Linker mutagenesis in the lacZ gene of Escherichia coli yields variants of active beta-galactosidase.
abstract: Synthetic octameric oligonucleotides that code for a unique restriction site were cloned into a randomly linearized plasmid that carries the lacZ gene. The insertions were mapped by digestion with appropriate restriction endonucleases. 12 mutants were identified which carry an insertion within the lacZ gene and still express active beta-galactosidase. Small deletions or duplications of the wild-type sequence occurred at these positions which restore the correct reading frame. The insertions occurred in the first and the last third of the internal duplication of the lacZ gene and within the domain homologous to dihydrofolate reductase.
authors.affiliation: Institut für Genetik, Universität zu Köln, Federal Republic of Germany.
authors.forename: A
authors.initials: A
authors.lastname: Breul
authors.forename: W
authors.initials: W
authors.lastname: Kuchinke
authors.forename: B
authors.initials: B
authors.lastname: von Wilcken-Bergmann
authors.forename: B
authors.initials: B
authors.lastname: Müller-Hill
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002872:Chromosome Deletion; D002874:Chromosome Mapping; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D005798:Genes, Bacterial; D014644:Genetic Variation; D007700:Kinetics; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D010957:Plasmids; D001616:beta-Galactosidase / Q000235:genetics* / Q000378:metabolism
chemical_list: D001616:beta-Galactosidase