RNA structure interactions and ribonucleoprotein processes of the influenza A virus

Dawson, Wayne K; Lazniewski, Michal; Plewczynski, Dariusz

Replication means making a complete unedited copy of the original viral genome (with possible mutations introduced by replication 'errors'). In the first step of replication, the vRNA sequence uses the original viral polymerase as an anchor and recruits a second free viral polymerase (in trans) to build a positive-sense copy of the vRNA sequence (vRNA ! cRNA). This is a complete positive-sense strand copy of the original segment. The final result is a complete vRNP that contains only the cRNA sequence. This new cRNA must be again replicated to obtain a negative-sense copy of the sequence (cRNA ! ccRNA ¼ vRNA), where ccRNA is the newly created complement of cRNA (which will serve as a vRNA for next generations of virus). This freshly made vRNA sequence must also have access to newly synthesized copies of M1, PA, PB1, PB2 and NP; hence, these proteins (generated by the transcribed mRNA products) must be imported back into the nucleus. The PA þ PB1 þ PB2 must assemble into a new viral polymerase, which together with the nascent NPs and vRNA is used to form the new vRNP [20, 44, 69] .