Transcriptional analysis of E. coli and E. chaffeensis RNAPs using p28-Omp 14 and 19 promoters. Transcription of pRG147 (lane 1), pRG147R (lane 2), pRG198 (lane 3), pRG198R (lane 4), pMT504 (lane 5) was assessed using E. coli holoenzyme or with E. coli core enzyme with pRG198 (lane 6). Transcription of pRG198 by HA-purified E. chaffeensis RNAP (lane 7); inhibition of transcription of E. chaffeensis RNAP by the addition of 4 μg of 2G10 (Ab); inhibition of transcription of E. chaffeensis RNAP by addition of 25 μg/ml of rifampin (Rf). Inhibition assays were performed using pRG198. GATC, sequencing ladder generated using the plasmid pRG198 sequenced with primer M13F-40 to serve as the molecular weight markers.