Figure 5.

In vivo assay of modified pentapeptides. Sporulation assays were carried out with the resuspension method of Sterlini and Mandelstam (23). (A) Strain JH12954 carrying a deletion of the PhrA coding gene was resuspended in the sporulation medium in the presence of peptides at 10 μM final concentration. The wild-type level of sporulation is given by strain JH642 (lane 1), whereas strain JH12954 grown in the absence of peptides is shown in lane 2. PhrApep5, PhrCpep5, pep 878, pep 879, pep 880, pep 881, pep 882, and pep 883 were added to the cultures represented in lanes 3–10, respectively, and the number of spores per ml is shown by the bars. (B) Strain JH642 carrying the rapB multicopy plasmid pIPB213A was grown in the presence of 5 μg/ml chloramphenicol (Cm). The wild-type control strain was JH642 carrying the multicopy vector pBS19 (lane 1). Lane 2 shows the level of sporulation of JH642/pIPB213A in the absence of peptides, whereas lanes 3–10 show the number of spores per ml obtained by the addition of peptides (10 μM) as in A.