TABLE 1.

Candidate toxins examined for inducible negative selection

Toxin	Source	Reference
Endogenous
MazF	TA module on S. mutans chromosome; arrests cell growth via RNA cleavage	30
SmuT	TA module on S. mutans chromosome; bactericidal via membrane permeabilization	31
Fst-sm	TA module on S. mutans chromosome; putative membrane permeabilization and/or inhibition of cell division	32
Exogenous
ParE	Addiction module of cryptic S. mutans plasmid pUA140; bactericidal via inhibition of DNA gyrase	33
RNase H	Housekeeping enzyme on E. coli chromosome; arrests cell growth via RNA cleavage	34