Physical maps of hlyA recombinant clones from the Lambda ZAP II genomic library. The plasmid designations are also given. The scale at the top is in kilobases. The sequences used for probing chromosomal DNAs are indicated by the heavy bar. The boxes represent open reading frames; the gray box is hlyA. The solid arrows indicate the direction of transcription. The dotted arrows indicate positions of the sequencing primers TV2 (left) and TV7 (right). Only AseI sites relevant to the hybridization probe are shown. ORF, open reading frame; A, AseI; C, ClaI; Ev, EcoRV; H, HindIII; P, PstI. Not shown is the EcoRI site in the vector multiple-cloning site on the right side of all clones.