Restriction digests of the clone give the following sizes (kb): BglI--4.4, 2.2; ClaI--6.6; EcoRV--6.6. The vector contains the following restriction sites (approximate kb from the EcoRI site): BglI--0.20, 2.50; ClaI--4.99, 5.03; EcoRV--4.72; NdeI--0.27, 2.09; PvuI--0.17; PvuII--0.14, 6.39; SmaI--4.98. The chloramphenicol resistance gene (catP), expressed in both C. perfringens and E. coli, was derived from C. perfringens and is inactivated by insertions at the EcoRV site. The standard reverse sequencing primer is not useful in this vector due to the duplication of the 181 bp region between pUC18 sites PvuII and EcoRI. Shuttle expression vector derived from pJIR418 (ATCC 77387) permitting expression of antibiotic resistance in both hosts. |