Abstract: 5-mer and 8-mer polypeptides have been demonstrated to inhibit peptidyl transferase and according constitutes synthetic antibiotics. Identified, sequence-specific peptides effective includeMet-Val-Lys-Thr-Asp (SEQ ID NO: 1),Met-Lys-Lys-Ala-Asp (SEQ ID NO: 2),Met-Lys-Lys-Ser-Glu (SEQ ID NO: 3) andMet-Ser-Thr-Ser-Lys-Asn-Ala-Asp (SEQ ID NO: 4)The polypeptides can be used as antibiotics, alone or together with a carrier.

Abstract: A double-stranded DNA plasmid which includes a promoter DNA sequence that is not derived from a B. subtilis plasmid and a DNA sequence derived from a B. subtilis plasmid is useful for introducing into B. subtilis foreign DNA having a nucleic acid sequence which does for the production of a desired product. Preferably, the promoter sequence is also not derived from B. subtilis chromosomal DNA. When a foreign DNA sequence having a nucleic acid sequence coding for production of a desired product is introduced into this plasmid, another plasmid is produced which is useful for effecting expression in B. subtilis of the foreign DNA and production of the desired product. The plasmids may additionally include an inducible gene.B. subtilis cells transformed with plasmids carrying a gene or genes coding for the production of desired products may be grown in culture and the resulting products recovered.

Abstract: The invention provides a mutant plasmid useful for introducing into B. subtilis foreign DNA, the nucleic acid sequence of which codes for production of a desired product. The plasmid is constructed from (1) a segment of B. pumllus DNA containing a chloramphenicol acetyltransferase gene plus an EcoRI* promoter fragment cloned from phage SPO2 DNA and a (2) portion of a B. subtilis plasmid, pUB110. The plasmid gives enhanced expression of genes coding for certain products, such as dihydrofolate reductase.