Bacillopeptidase F of Bacillus subtilis: purification of the protein and cloning of the gene

We have purified a minor extracellular serine protease from Bacillus subtilis. Characterization of this enzyme indicated that it was most likely the previously reported enzyme bacillopeptidase F. The amino-terminal sequence of the purified protein was determined, and a "guess-mer" oligonucleotide hybridization probe was constructed on the basis of that sequence. This probe was used to identify and clone the structural gene (bpr) for bacillopeptidase F. The deduced amino acid sequence for the mature protein (496 amino acids) was preceded by a putative signal sequence of 30 residues and a putative propeptide region of 164 amino acids. The bpr gene mapped near pyrD on the chromosome and was not required for growth or sporulation.

Gene encoding a novel extracellular metalloprotease in Bacillus subtilis

The gene for a novel extracellular metalloprotease was cloned, and its nucleotide sequence was determined. The gene (mpr) encodes a primary product of 313 amino acids that has little similarity to other known Bacillus proteases. The amino acid sequence of the mature protease was preceded by a signal sequence of approximately 34 amino acids and a pro sequence of 58 amino acids. Four cysteine residues were found in the deduced amino acid sequence of the mature protein, indicating the possible presence of disulfide bonds. The mpr gene mapped in the cysA-aroI region of the chromosome and was not required for growth or sporulation.

Transformation of Bacillus subtilis by single-stranded plasmid DNA

The single-stranded form of a pE194-based plasmid transformed Bacillus subtilis protoplasts at least as efficiently as did the double-stranded plasmid, but the single-stranded form did not detectably transform B. subtilis competent cells.

Cosmid DNA packaging in vivo

The packaging of cosmid DNA into phage particles during phage lambda growth is described. Evidence is presented supporting the work of others that cosmid transducing phages contain linear multimers of cosmid DNA in which the number of cosmid copies is that required to make a packagable DNA length (greater than 0.77 of the lambda DNA length). The yield of cosmid transducing phages declines sharply as the number of cosmid copies required to make a packagable DNA length increases. The cosmid DNA replication that produces the packaging substrate shares with lambda rolling-circle replication a dependence on the lambda gam gene product.

Identification of the C. coli dnaK (groPC756) gene product

The E. coli dnaK (groPC756) gene product is essential for bacteriophage lambda DNA replication. Bacterial DNA segments carrying this gene have been cloned onto a bacteriophage lambda vector. The product of the dnaK gene has been identified on SDS polyacrylamide gels after infection of UV-irradiated E. coli cells. The dnaK gene codes for a polypeptide with an apparent molecular weight of 93,000-Mr. Transducing phages carrying amber mutations in the dnaK gene fail to induce the synthesis of the 93,000-Mr polypeptide chain upon infection of sup+ bacteria, but do so upon infection of supF bacteria. E coli carrying the dnaK756 mutation are, in addition, temperature sensitive for growth at 43 degrees C. It is shown that the dnaK756 mutation results in an overproduction of the dnaK gene product at that temperature.