FIG. 5.
Expression of the GusB and GusC proteins in tac and OLPL promoter systems. Cells containing the plasmids indicated below were grown and membrane preparations were made; 1.0 mM IPTG was included for induction of the tacpromoter and 40 μg of nalidixic acid per ml for induction of the OLPL promoter where indicated. Total membrane protein was solubilized at 100°C for 4 min and 45 μg was loaded onto each track of the SDS--12% bisacrylamide gel. Lane 1, tac-gusBCCE1 induced; lane 2, tac-gusBCCE1 uninduced; lane 3, vector pTTQ18 plus IPTG; lane 4, OLPL gusBCCE1 induced; lane 5, OLPL gusBCCE1 uninduced; lane 6, OLPL gusBCE1 induced; lane 8, OLPL gusCCE1 induced; lane 10, vector pAD284 plus nalidixic acid.