A series of shuttle vectors for Bacillus subtilis and Escherichia coli was developed. These are derived from one basic construct composed of parts of the Gram+ plasmid pUB110 and the Gram- plasmid pBR322. They contain multiple cloning sites flanked by transcriptional terminators. In one plasmid, a vegetative B. subtilis promoter drives transcription of inserted genes. For the construction of operon and gene fusions, the cat of pUB112 and the lacZ gene of E. coli were employed as reporter genes. With these vectors, cloning and expression of genes as well as probing of regulatory signals can be performed in B. subtilis and E. coli.