Table 2.

Effects of the Tet(L) and Tet(K) mutations on protein assembly into the membrane and Tc-resistance in E. coli DH5α^a

Tet(L) or Tet(K)	Location of mutation	Protein property	% Membrane Assemblyb	MIC of Tcc (μg/ml)
-	-	None (vector control)	-	2
Tet(L)	None	Wild-type	100	30
	Motif B, TMS IV	R110Cd	18	2
		R110K	82	4
	Motif C, TMS V	E152C	30	2
		E152D	49	12
		E152Qd	98	3
		G155A	134	16
		G155C	100	8
		G155S	152	8
		P156A	60	2
		P156C	94	2
		P156G	121	2
	Motif H, TMS VI	P175A	89	8
		P175Cd	88	16
		P175G	74	16
	TMS X	P301G	NDe	>32
		P301S	86	2
		G302A	76	8
		G302C	62	2
		T303A	66	8
	TMS XIII	G398C	80	16
		G400C	73	8
		G405C	60	2
		G406C	65	8
Tet(K)	Motif C, TMS V	Wild-type	100	12
		G155C	105	4
		G155S	88	8
		P156C	98	2

^aAll values are the average of duplicate determinations in at least two independent experiments, with standard deviations ≤15% of the mean.

^bPercentage of the wild-type values (set at 100) as evaluated by Western analyses.

^cMIC is minimal Tc concentration at which there was no growth of the E. coli DH5α transformant after a 15-h incubation in rich medium (41).

^dThese values have been reported previously , and are shown here for comparison.

^eNot determined.