Structural elements of the 3'-terminal coat protein binding site in alfalfa mosaic virus RNAs.

Viral coat protein peptides with limited sequence homology bind similar domains of alfalfa mosaic virus and tobacco streak virus RNAs.

An unusual and distinguishing feature of alfalfa mosaic virus (AMV) and ilarviruses such as tobacco streak virus (TSV) is that the viral coat protein is required to activate the early stages of viral RNA replication, a phenomenon known as genome activation. AMV-TSV coat protein homology is limited; however, they are functionally interchangeable in activating virus replication. For example, TSV ...

Partial Epitope Mapping of Alfalfa mosaic Virus and the Effect of Coat Protein Gene Mutation on Aphid Transmission

Functional Equivalence of Common and Unique Sequences in the 39 Untranslated Regions of Alfalfa Mosaic Virus

The 3* untranslated regions (UTRs) of alfalfa mosaic virus (AMV) RNAs 1, 2, and 3 consist of a common 3*-terminal sequence of 145 nucleotides (nt) and upstream sequences of 18 to 34 nt that are unique for each RNA. The common sequence can be folded into five stem-loop structures, A to E, despite the occurrence of 22 nt differences between the three RNAs in this region. Exchange of the common se...

Mutations in coat protein binding sites of alfalfa mosaic virus RNA 3 affect subgenomic RNA 4 accumulation and encapsidation of viral RNAs.

The 3'-untranslated regions (3'-UTRs) of the three RNAs of alfalfa mosaic virus (AMV) contain a specific binding site for coat protein (CP) and act as a promoter for minus-strand RNA synthesis by the purified AMV RNA-dependent RNA polymerase (RdRp) in an in vitro assay. Binding of CP to the viral RNAs is required to initiate infection. The sequence of the 3'-terminal 39 nucleotides of AMV RNA 3...

Coat protein activation of alfalfa mosaic virus replication is concentration dependent.

Alfalfa mosaic virus (AMV) and ilarvirus RNAs are infectious only in the presence of the viral coat protein; therefore, an understanding of coat protein's function is important for defining viral replication mechanisms. Based on in vitro replication experiments, the conformational switch model states that AMV coat protein blocks minus-strand RNA synthesis (R. C. Olsthoorn, S. Mertens, F. T. Bre...