Table 2.

HEV-encoded proteins and their (putative) functions.

HEV-encoded proteins	Confirmed functions	Crystral structure?	References
ORF1	Non-structural proteins
Methyltransferase	Guanyltransferase, guanine-7-methyltransferase	No	Magden et al. (2001)
Papain-like cystein protease	Proteolytic processing of ORF1? Deubiquitinating activity	No	Karpe and Lole (2011), Parvez, 2013, Perttilä et al., 2013 and Sehgal et al. (2006)
Hypervariable region	Influences efficiency of viral RNA replication, host/cell type specificity?	No	Pudupakam et al. (2011) and Shukla et al. (2012)
Macrodomain	Poly-ADP-ribose-binding, weak ADP-ribose 1″-phosphohydrolase activity	No	Egloff et al. (2006)
Helicase	5′–3′ RNA unwinding, NTPase, RNA 5′-triphosphatase	No	Karpe and Lole, 2010a, Karpe and Lole, 2010b
RdRp	RNA-dependent RNA polymerase activity	No	Agrawal et al. (2001) and Rehman et al. (2008)
ORF2	Capsid protein	Yes (HEV-like particle)	Guu et al. (2009) and Yamashita et al. (2009)
ORF3	Interaction with multiple cellular proteins, including Tsg101, hemopexin,…Suppression of interferon-α signalingParticle egress	No	Geng et al., 2013, Ratra et al., 2008, Surjit et al., 2006, Dong et al. (2012) and Yamada et al. (2009)