TABLE 2.
IS492 excision from the eps target sequence in E. coli
| Plasmid(s) | IS492 genotype (source of MooVa) | Cells/ml
|
Frequency of excision (Cmr/Tetr) | Circle formation (PCR assay) | |
|---|---|---|---|---|---|
| Tetrb | Cmrc | ||||
| pAG993 | Wild type (IS492+) | 6.0 × 107 | 5.7 × 107 | 0.95 | + |
| pAG994 | ΔmooV (IS492ΔmooV::lacZ) | 1.4 × 108 | 0 | 0 | − |
| pAG994, pMalC-2 | ΔmooV | 2.6 × 108 | 0 | 0 | − |
| pAG994, pMal-MooV | ΔmooV (malE-mooV) | 2.3 × 108 | 2.0 × 103 | 0.87 × 10−5 | + |
| pAG992.2 | Excisant (IS492−)d | 1.3 × 108 | 1.3 × 108 | 1.00 | − |
a
Plasmids were maintained in E. coli TOP10 cells (see Materials and Methods).
b
Cultures were grown in LB broth without IPTG, and dilutions were plated on LB agar containing 12.5 μg of tetracycline per ml.
c
The same culture dilutions were plated on LB agar containing 80 μg of chloramphenicol per ml.
d
pAG992.2 is the product of precise excision of IS492 from pAG993.