Abstract
In vivo and in vitro recombination techniques were used to construct a new cloning vector, pHY300PLK (4.7 kb) from the shuttle vector pHY460 (7 kb). The newly derived shuttle vector can replicate and express the tetracycline resistance gene (TcR) in both Escherichia coli and Bacillus subtilis. pHY300PLK contains the TcR gene, the ampicillin resistance gene (ApR), two replication origins for E. coli and B. subtilis and a polylinker derived from .pi.AN7. The unique cloning sites are BalI, BamHI, BanI, BglI, BglII, BstEII, EcoRI, EcoRV, HindIII, HpaI, SalI, SmaI, PvuI and XbaI. pHY300PLK is characterized as a copy-number mutant in E. coli.