FIG. 1.

Construction of pJDM-STM vector. pJDM-STM was derived from pMGC57 which contains the modified Tn4001 transposon (34). The erythromycin resistance gene was placed within an omega cassette (39) and modified to contain unique ApaI and NotI restriction sites for insertion of specific signature tags. For details, see Materials and Methods. Sites for restriction enzymes are indicated as follows: B, BamHI; S, SmaI; E, EcoRI; N, NotI; A, ApaI; H, HindIII. PCS, polycloning site; Erm, erythromycin resistance gene; PaphA3; promoter for kanamycin resistance gene aphA3; Kan, kanamycin resistance gene; CmR, chloramphenicol resistance gene; ori, origin.