Figure 4

Construction of the insertion plasmid pSMB148. pSMB139 was constructed by introducing a 2.0 kb fragment, containing a transcriptional fusion of PP promoter with emm6, in the Tn916 insertion vector pSMB47 (see Methods). pSMB148 is a derivative of pSMB139 in which a 900 bp AvrII-HindIII fragment was replaced with a 390 bp AvrII-HindIII fragment from pSMB55 containing a multiple cloning site [10].