Table 1.

Type IV pilin proteins in select model systems

Component	Pilin protein(s)			References
Type IVa pili	Pseudomonas aeruginosa	Neisseria spp.	Vibrio cholerae (MSHAa)
Major subunit	PilA	PilE	MshA	270, 282, 307
Core minor subunits	FimU, PilV, PilW, PilX	PilH, PilI, PilJ, PilK	MshB, MshC, MshD, MshO	13–15, 270, 416
Noncore minor subunits	PilE	PilX (PilL), PilV, ComP		175, 340, 415
Prepilin peptidase	PilD	PilD	VcpD	146, 271, 298
Type IVb pili	EPECb (bundle-forming pili)	Vibrio cholerae (Tcpc)	R64 thin pili
Major subunit	BfpA	TcpA	PilS	123, 135, 221
Core minor subunits	BfpI, BfpJ, BfpK	TcpB	PilV	221, 265, 368
Prepilin peptidase	BfpP	TcpJ	PilU	221, 246, 368
Tad pili	Aggregatibacter actinomycetemcomitans	Caulobacter crescentus	Pseudomonas aeruginosa
Major subunit	Flp	PilA	Flp	117, 210, 359
Core minor subunits	TadE, TadF	NAd	TadF	42, 393
Prepilin peptidase	TadV	CpaA	FppA	117, 359, 392
Type II pseudopili	Klebsiella oxytoca	Vibrio cholerae	Pseudomonas aeruginosa
Major subunit	PulG	EpsG	XcpT	299, 331, 347
Core minor subunits	PulH, PulI, PulJ, PulK	EpsH, EpsI, EpsJ, EpsK	XcpU, XcpV, XcpW, XcpX	299, 331, 347
Prepilin peptidase	PulO	VcpD	XcpA	37, 271, 321

^aMannose-sensitive hemagglutinin pili.

^bEnteropathogenic E. coli.

^cToxin-coregulated pili.

^dNA, not applicable.