FIG. 6.

Regulation of gene expression in the RA3 replication region. DNA fragments cloned into promoter probe vector pPTO1 and tested for promoter activity are shown. Units of XylE transcriptional activity were measured in extracts from IPTG-induced logarithmic-phase cultures of double transformants of C600K with pPTOI or its derivatives and expression vector pGBT30 and its derivatives pMOB1.5.1 (tacp-repA) and pMOB1.6.1 (tacp-repB). The results shown are averages from at least five experiments. ND, not determined.