Table 1. An outline of evidences that vmi480 and vmi470 constitute a TA module.

Aspects	Evidences
Genetic analysis	1. vmi480 and vmi470 constitute an operon with their own promoter and their genetic configuration resemble those of most type II TA systems.
	2. vmi470 contains a DNA-binding helix-turn-helix domain shared by several antitoxins.
Deletion mutants	3. Deletion of vmi480 or vmi480-vmi470 can be achieved while deletion of sole vmi470 cannot fulfill.
Ectopic expression	4. Sole expression of vmi480 is lethal to the cells.
	5. Sole expression of vmi470 has no effect on cell growth.
	6. Lethality of Vmi480 can be eliminated when both genes are co-expressed in one vector.