We determined the secondary structure of the cRNA of influenza A virus RNA promoter and observed its dynamic nature using NMR spectroscopy. cRNAs of influenza A virus RNA genomes are full length copies of viral genomes and templates of viral RNAs synthesis. Although the cis-acting signals responsible for the switching from transcription to replication and initiation/termination of transcription are believed that they are located in the 5` and 3` terminals of viral RNAs, a mechanism of switching from transcription to replication and mechanisms of initiation/termination of transcription have not been known well. We compared secondary structure of cRNA promoter used only in the replication process with that of vRNA promoter to explain those mechanisms in this thesis. We showed that the terminal region of cRNA promoter was less stable than vRNA promoter in the aspect of the structural and the dynamic nature. Also We found that the internal loop region of two RNA promoter has some common structural and dynamic properites and observed the signal for conformational change of the internal loop of cRNA promoter which may implied that these dynamic characters were related with the recognition and induced-fit of PB1 subunit. We suggested the vRNA synthesis from cRNA templates was more effective due to properties of cRNA promoter and the switching mechanism from transcription to replication base on our results and previous biochemical studies.
