Plant viral movement proteins bind to RNA and participate in the intra- and intercellular movement of the RNAs from plant viruses. However, the role and magnitude of the conformational changes associated with the formation of RNA-protein complexes are not yet defined. Here we describe studies on the relevance of a preexisting nascent alpha-helix at the C terminus of the RNA-binding domain of p7, a movement protein from carnation mottle virus, to RNA binding. Synthetic peptide analogues and single amino acid mutation at the RNA-binding domain of recombinant p7 protein were used to correlate the transient structural order in aqueous solution with RNA-binding potential.