Fig. 5

Analyses of viral genomic region containing 5′-MSD motif. a The presence of a unique GT-to-GC mutation at the 5′-MSD motifs of residual vDNA clones. Only a region spanning the 5′-MSD junction was taken from each vDNA sequences and aligned with the corresponding sections of the three standard HIV strains (top). The 5′-MSD motif mutation (GT-to-GC) in each vDNA clone is shown within the vertical box. b Illustration of the conserved splicing motifs present in HIV genomic RNA. Bold underlined GU, A and AG represent 5′-major splice donor (5′-MSD) site, branch-point, and a 3′-splice acceptor sites (3′-SA), respectively. Generally, such sites are also utilized during mRNA splicing in eukaryotes. The R and U5 regions belong to the HIV long-terminal repeat (LTR). The ‘non-coding exon 1’ is always combined with the polyadenylated [poly(A)] ‘exonic’ portion of vRNA upon splicing