The structure of barley stripe mosaic virus double‐stranded RNAs

Abstract

The terminal structures of the double-stranded replicative forms (RFs) of barley stripe mosaic virus (BSMV) RNAs 1-3 have been investigated. All three BSMV RFs have identical right-hand ends but unique left-hand ends. The plus (+) strands of RFs lack the 3'-ultimate A typical for the encapsidated BSMV RNAs. The 3'-termini of the minus (-) strands contain an unpaired G. It was demonstrated that the internal poly(A) tract of BSMV genome has an equivalent poly(U)-counterpart in the RF (-) strands. The possible role of these peculiarities of BSMV RF structure in RNA replication is discussed.RNA; Barley stripe mosaic virus; double-stranded RNA; Poly(A) sequence; (Plant virus)

A Non-capsid Protein Associated with Unencapsidated Virus RNA in Barley Infected with Barley Stripe Mosaic Virus

“…Small amounts of unencapsidated virus RNA should theoretically be present in translation, replication and transport complexes in tissue at the appropriate stages of infection. The presence of BSMV RNA in replication and translation complexes is indicated because polysomes from BSMVinfected plants synthesize virus proteins (Gustafson et al, 1981) and dsRNA has been isolated from infected plants (Pring, 1972;Jackson & Brakke, 1973;Dolja & Atabekov, 1987). Unencapsidated virus RNA extracted with high pH, high salt buffers from infected tissue may originate from such complexes (Diener, 1962;Brakke, 1972).…”

Gene expression from viral RNA genomes

“…High levels of dsRNA have been described for the sgRNA of TNV [116], BYDV [94] and RCNMV [132]. A detailed study of the dsRNA forms of the PVX and BSMV sgRNAs has been carried out [47,46]; the 3 J end of the (-) strand of the gRNA has an extra unpaired G residue as compared to the (+) strand, this extra nucleotide being necessary for new synthesis of (+) strand gRNA. On the contrary the 3 t end of the (-) strand of the sgRNA in the ds form lacks this extra nucleotide and both strands are perfectly matched at this end, abolishing production of sgRNA through bona fide replication from a sgRNA template.…”

Potato virus X‐related single‐ and double‐stranded RNAs

“…The 3'-terminus of the (-) chain also ends in G. Therefore the 'left' end of the RF cannot be 'blunt'. In all probability it is the extra G in the To date, the extra G has already been found at the 3' -termini of the RF ( -) chains in two groups of plant viruses: cucumo- [15], and hordeiviruses [16].…”