Restriction map and complementation data for
The restriction map for pmarD and the positions of the mprA, emrA, and emrB genes are shown at the top. pmarD is pBluescript SK− (Stratagene) derivative containing a 6.0-kb fragment from a random SauIIIA digest of chromosomal DNA of E. coli strain W3110. Specific subclones were generated as described in Materials and Methods. marR complementation indicates the ability of the specified plasmid to restore a Lac− phenotype on MacConkey-lactose media to strain B318.