TABLE 3.

Activity of CdaS variants

Intracellular c-di-AMP was determined from E. coli cultures harboring the indicated expression vectors (pET28a derivates). Cultures were grown in LB medium, and c-di-AMP amounts were determined using HPLC/MS as described under “Experimental Procedures.” Each value is the mean of three independent experiments. S.D. are given in parentheses.

Vector	Mutation	ng c-di-AMP/mg protein
pET28a	Empty vector	0 (0)
pGP1974	WT	623 (35)
pGP1975	L44F	56,400 (11,480)
pGP2553	E46K	12,196 (140)
pGP1995	A61V	7,250 (2,525)
pGP1998	A76V	2,700 (463)
pGP2552	P201Q	7,970 (463)
pGP1993	ΔH1	12,500 (1,195)
pGP1994	ΔH2	10,500 (1,053)