Structural diversity and biological role of the 5’ untranslated regions of picornavirus

RNA structure: implications in viral infections and neurodegenerative diseases

“…There is a more detailed review that discusses how viral RNA structures manipulate RNA translation (Jaafar and Kieft 2019). Different RNA virus families are characterized by distinct IRES elements which have been reviewed by other reviews (Peng et al 2023;Niepmann and Gerresheim 2020;Nakashima and Uchiumi 2009;Lozano and Martínez-Salas 2015). One study uses RNase V1 probing to determine the 5' UTR in SARS-CoV-2 and found that there is a highly stable four-way junction in this region, which may be involved in translation initiation (Miao et al 2021).…”

The multiple roles of viral 3D pol protein in picornavirus infections

“…The genomes of the Picornaviridae family have similar backbones, with a positive-stranded RNA genome between 6.7 kb and 10.1 kb in size and a single open reading frame (ORF) flanked by untranslated regions (UTRs) [ 11 , 12 ]. As shown in Figure 1 , the 5” end of the genome is linked to VPg, which can be uridylated by the 3D pol protein to act as a primer for transcription [ 1 , 13 ].…”

“…All Picornaviridae members have a single ORF, which translates a polyprotein that is cleaved by the viral proteases 2A pro , 3C pro , and 3 CD pro into the precursor proteins P1, P2, and P3 [ 14 , 16 ]. The P1 precursor protein is then cleaved into four structural proteins, which we have designated VP1, VP2, VP3, and VP4; the P2 precursor protein is processed into nonstructural proteins 2A pro , 2B, and 2C; and the P3 precursor protein undergoes proteolytic cleavage into nonstructural proteins 3A, 3B, 3C pro , and 3D pol [ 12 ]. Some picornaviruses, such as aphthoviruses, cardioviruses, and kobuviruses, additionally express a leader protein (L pro ) at the N-terminal end of the polyprotein, after which the polyprotein is cleaved to form the L pro , P1, P2, and P3 precursor proteins [ 17 ].…”