Table 2.

Types of 3′ end cap-independent translation enhancers (3′ CITEs) and their brief characteristics

3′ CITE type	Family (Genus) of viruses	Interaction with 5′ end of gRNA	Bind	Kd, nM
BTE B YDV like T ranslation E nhancer	Luteoviridae (Luteovirus); Tombusviridae (Necrovirus, Dianthovirus, Umbravirus*)	Yes (RCNMV ?)**	eIF4G eIF4F	177 [180] 37 [180]
TED T ranslation E nhancer D omain	Not attributed (Albetovirus); Tombusviridae (Carmovirus)	Yes (STNV ?)**	eIF4F eIFiso4F eIF4E eIF4isoE	17-30 [181] 33-50 [181] 780 [181]; 313 [182] 660 [181]
PTE P MV-like T ranslation E nhancer	Tombusviridae (Panicovirus, Carmovirus, Aureusvirus, Umbravirus*)	Yes (PEMV-2 no)	eIF4E eIF4F	58 [182] 48 [182]
ISS I-ShapedStructure	Tombusviridae (Tombusvirus, Carmovirus, Aureusvirus)	Yes	eIF4F	190 [183]
YSS Y-ShapedStructure	Tombusviridae (Tombusvirus)	Yes	eIF4F eIFiso4F	[184]*** [184]***
TSS T-ShapedStructure	Tombusviridae (Carmovirus, Umbravirus*)	No	60S 80S	340 [185]; 233 [186] 450 [185]; 300 [187]; 1720 [186]
kl-TSS kissingloopT-ShapedStructure	Tombusviridae (Umbravirus*)	Yes	40S 60S 80S	360 [186] 300 [186] 520 [186]; 610 [188]

Notes: * Assignment to Tombusviridae is provisional: umbraviruses contain two gRNAs and only one of them (which carries 3′ CITE) resembles other members of this family.

** In this case mutation analysis did not confirm the predicted kissing interaction with a 5′ proximal hairpin.

*** Factor binding was demonstrated by a non-equilibrium method.