( B ) - Galactosidase activity from GolS-or CueR-regulated transcriptional-fusions golB : : lacZ ( PgolB ) or copA-lacZ ( PcopA ) , respectively , on cells carrying either wild-type golS and cueR , or golSL , golSsL , or golSC111S , replacing the wild-type copy of golS , or cueRL , replacing cueR .