TABLE 2.

Putative functions of PAPI-1 Pil proteins

Gene	Gene product	Mutant strain(s)a	Transfer efficiency	Conserved domainb	Homologous component(s) of TFp/T4SS	Description (reference)
PA14_59240	PilL2	PA14TnΩ241pilL2	<10−8	None	Type IV lipoprotein PilL	Lipoprotein (29)
PA14_59250	PilN2	PA14TnΩ47pilN2	<10−8	Secretin, bacterial type II and III secretion system protein (pfam00263)	Type IV pilus secretin protein PilN	Secretin (29)
PA14_59270	PilO2	PA14TnΩ111pilO2	<10−7	PAP_PilO, pilin accessory protein (pfam06864)	Pilus accessory protein PilO	Outer membrane protein (30)
PA14_59280	PilP2	PA14TnΩ344pilP2	<10−7	Pilus_PilP superfamily (pfam11356)	Pilus assembly protein PilP	Periplasmic or outer membrane protein (30)
PA14_59290	PilQ2	PA14TnΩ241pilQ2	<10−7	P-loop nucleoside triphosphatase superfamily	TFp pilus assembly protein PilT, pilus retraction ATPase (COG2805)/VirB11-like ATPase (cd01130)	ATPase
PA14_59310	PilR2	PA14TnΩ37pilR2	<10−7	GSPII_F, bacterial type II secretion system protein F domain (pfam00482)	Plasmid R64 integral membrane protein PilR	Membrane protein (30)
PA14_59320	PilS2	PA14TnΩ103pilS2	<10−7	PilS superfamily (pfam08805)	Type IV prepilin PilS	Pilin protein
		PA14 ΔpilS2	<10−8
		PA14 ΔpilS2ppilS2	1.7 × 10−5
PA14_59340	PilT2	PA14TnΩ44pilT2	<10−7	P-loop nucleoside triphosphatase superfamily	TFp pilus assembly protein PilT, pilus retraction ATPase (COG2805)/VirB11-like ATPase (cd01130)	ATPase
PA14_59350	PilV2	PA14TnΩ103pilV2	<10−7	Shufflon_N superfamily (pfam04917)	Plasmid R64 minor pilin subunit PilV	Shufflon protein (17)
		PA14 ΔpilV2	<10−8
		PA14 ΔpilV2ppilV2	8.5 × 10−5
PA14_59360	PilM2	PA14TnΩ59pilM2	<10−8	PilM (pfam07419)	Plasmid R64 inner membrane protein PilM	Membrane protein (30)

^aThe number indicates the insertion site of the transposon in the gene.

^bRevealed by PSI-BLAST analysis.