TABLE 1.

Plasmids used in this study and their relevant properties

Plasmid(s) in donor strain HB101	Properties	Antibiotic resistance carried	Transfera	Junctions detected
RP4	Wild-type	Kanamycin	+	+
pML123, pVWDG23110Δ0.2	Tra1 + Tra2	Chloramphenicol, kanamycin	+	+
pML123, pWP471	Tra2 + protease TraF (pili processed)	Chloramphenicol, ampicillin	−	±
pML123	Tra2 only (pili unprocessed)	Chloramphenicol	−	±
pML123mtrbC45	Pilin− mutant (MURFI linker in trbC)	Chloramphenicol	−	+
None	—	None	−	−

^aTransfer, whether DNA transfer properties can be demonstrated in quantitative matings (10, 13, 17).