Table 1. Strains and Plamids used in this Study.

Strain or Plasmid	Relevent characteristic	Reference or Source
Plasmids
Litmus 28	Cloning vector AmpR	New England Biolabs
PVK50	Litmus28 with A. actinomycetemcomitans uptake sequence, AmpR	Dr. Kablilan VelliyagounderThis work
pHS 65	pVK50 with parts of cdtA and cdtB, AmpR	This work
pHS 66	pHS65cdtB::tn5<KAN -2> AmpR KamR	This work
PET100/D-TOPO	Protein cloning and expression vector, AmpR	Invitrogen
Aa1700	LtxA mutant of NJ2200	[30]
A. actinomycetemcomitans Strains
IDH781nal	A. actinomycetemcomitans clinical isolate, serotype d NalR	[29]
HS1030	IDH781nal cdtB::tn5<KAN -2> KamR NalR	This work
HS1031	HS1030 spontaneous RifR mutant	This work
DF2200rif	NJ2200 spontaneous RifR	[38]