Methods and compositions are provided for amplifying RNA from an RNA
template. Methods and compositions are further provided for detecting an
RNA in an RNA containing sample. Compositions used for the amplification
of RNA from RNA include a RNA-dependent RNA-polymerase, a RNA helicase,
and an energy source. Illustrative RNA-dependent RNA-polymerase enzymes
are derived from the tomato or tobacco plant, while illustrative RNA
helicase enzymes include the eIF4A and eIF4B proteins.