passages.id: split_5_test_2703_passage
passages.type: progene_text
passages.text: To investigate the function of ArcR in the differential expression of the arc operon , arcR was insertionally inactivated by a KM resistance marker flanked by T4 transcription / translation termination signals , and the expression of ParcA was monitored by primer extension in the wild - type and ArcR - deficient strains .