TABLE 2.

T6SS effector proteins from Escherichia coli.

Effector	E. coli pathotype	Target	Effector activity	Gene	References
AaiC	EAEC	Unknown (secreted)	Unknown (Hcp homologs)	BQ8769_135	Dudley et al., 2006
Rhs-CT1	STEC	Prokaryotic	Metalloprotease	CRM83_12975	Ma et al., 2017b
Rhs-CT3	ETEC	Prokaryotic	Restriction endonuclease-3	rhsA_2	Ma et al., 2017b
Rhs-CT5	EHEC	Prokaryotic	RNAase (Toxin_55)	Z5014	Ma et al., 2017b
KatN	EHEC	Eukaryotic	Catalase intramacrophage survival	Z1921	Wan et al., 2017
Tle1	EAEC	Prokaryotic/Eukaryotic	Type VI lipase toxin	EC042_4534	Journet and Cascales, 2016
Tle4	APEC	Prokaryotic	Type VI lipase toxin	YP_542179	Ma et al., 2014
Hcp-1	NMEC	Eukaryotic	HBMECs	G8IRM9_ECOLX	Zhou et al., 2012
Hcp1, Hcp3	ExPEC	Eukaryotic	Bacterial–eukaryotic cell interactions	NZ-CP006632.1 (0225 & 4211)	Peng et al., 2016
Hcp2	ExPEC	Prokaryotic	Bacterial competition	NZ-CP006632.1 (0245)	Peng et al., 2016
Hcp-ET1	STEC	Prokaryotic	HNH-DNase	AAF13_24945	Ma et al., 2017a
Hcp-ET2	ETEC	Prokaryotic	Tle1 phospholipase	A31K_02346	Ma et al., 2017a
Hcp-ET3-4	UPEC	Prokaryotic	Pyocin S3 and colicin DNase	UTI89_C0121	Ma et al., 2017a
XmtU	APEC	Prokaryotic	peptidase_C39 toxin	AHW84522	Ma et al., 2017b
VT1	ETEC	Prokaryotic	Amidase	KX118292	Ma et al., 2017a
VT5	ETEC	Prokaryotic	Lysozyme-like	KX118293	Ma et al., 2017a
VgrG1, VgrG2	ExPEC	Prokaryotic/eukaryotic	Antibacterial and virulence phenotypes	PCN033_0247 PCN033_1587	Zong et al., 2019