The phasmid as a tool for plasmid genetics: I. Fine structure of the β-lactamase gene

Abstract

SUMMARYThe reversible integration of a plasmid into a phage genome viaint-mediated recombination permits rapid and facile analysis of plasmid genes. Seventy-six independent mutants in theβ-lactamase(bla) gene have been isolated and genetically mapped. The end points of deletions generated by partial digestion with restriction enzymes have been identified and this, together with the assignment of some nonsense mutations to specific amino acid residues, allows alignment of the genetic map with the DNA sequence.