ThepHY300PLK E. coli-Bacillus shuttle vector is constructedfromthe E. coli-derived plasmid pACYC177 andthe Streptococcus faecalis-derived plasmid pAMa1. As a result, this vector can be used to transform both E. coli and Bacillus subtilis.The pHY300PLK vector contains both theampicillin resistance and tetracycline resistance genes as selective markers; whileboth of these resistance genes can be expressed in E. coli, only the tetracycline resistance gene can be expressed in B. subtilis.