Coupled mutations in the 5'-untranslated region of the Sabin poliovirus strains during in vivo passages: structural and functional implications
1991; Elsevier BV; Volume: 21; Issue: 2 Linguagem: Inglês
10.1016/0168-1702(91)90002-d
ISSN1872-7492
AutoresArkady R. Muzychenko, Galina Yu. Lipskaya, Svetlana V. Maslova, Yuri V. Svitkin, Evgeny V. Pilipenko, Baldev K. Nottay, Olen M. Kew, Vadim I. Agol,
Tópico(s)Viral gastroenteritis research and epidemiology
ResumoAll entero- and rhinovirus RNAs sequenced thus far possess A and U residues at positions corresponding to nucleotides 480 and 525, respectively, of poliovirus type 1. These two nucleotides have been proposed previously to form a base pair. The single exception to this rule appears to be the Sabin type 1 strain, which has a G480. Isolates of the Sabin 1 virus from healthy vaccinees were shown to have either a reversion to A480 or a second-site mutation U525----C, both restoring a potential for efficient base pairing. In vitro translation experiments demonstrated that poliovirus type 1 RNAs with either A480-U525 or G480-C525 are more efficient in promoting translation initiation as compared with the Sabin 1 RNA (G480-U525). The Sabin 2 strain has a U and an A at position 398 and 481, respectively, while its predecessor, strain P712, is shown to have C398 and G481. All the derivatives of the Sabin 2 isolated from vaccine-associated paralytic poliomyelitis cases shown reversion to G481, and most of them reverted also to C398. It is proposed that bases at positions 398 and 481 may be involved in a tertiary interaction. The in vitro template activity of the Sabin type 2 RNA (A481) is significantly lower than that of the isolate RNAs with G481, thus confirming the relation between attenuation and translation efficiency demonstrated previously for the type 1 and type 3 Sabin strains. The C----U change at position 398 exerted only a minor effect on the RNA template activity.
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