TABLE 3.

Effects of lacK′-′malK hybrids on maltose transport and mal gene expression^a

Plasmid	Protein synthesized	Maltose uptake (% of control)	β-Galactosidase activity (% recovered)
pSE380	None	3 ± 0.3	100
pSW7	MalK	100	6 ± 0.5
pGS96-22	LacK	17 ± 2.8	101 ± 1.6
pGS97-30	LacK′-′MalK1	125 ± 6.9	15 ± 2.4
pGS97-14	LacK′-′MalK2	26 ± 3.8	22 ± 0.6
pGS97-24	LacK′-′MalK3	3 ± 0.3	36 ± 1.4
pGS97-31	LacK′-′MalK4	3 ± 0.3	50 ± 0.3

^aThe effect of plasmid-encoded LacK′-′MalK chimeras on transport activity was measured for S. typhimurium ES25 (malK) (100% = 1.17 ± 0.14 mol/min/10⁹ cells). The effect on the expression of malK-lacZ was measured for E. coli SK1280 (100% = 229 ± 5.5 Miller units). Values are means ± standard deviations of three and four independent experiments, respectively.