RNA polymerase has many weak points of RNA viruses

Viruses evolve. Even if we make a good drug against a pathogenic virus, suddenly a new virus emerges. Scientists should make the drug against it again. To solve this problem, we should know the weak points of viruses. The unchangeable amino acids of many viruses are candidates for the weak point. In case of RNA virus, RNA polymerase, which is the enzyme for increase of the viral RNA genome, has many critical sites for viral growth. This means that the polymerase has many unchangeable amino acids because viruses should keep the critical sites for their growth. Thus, the RNA virus polymerase is not only important for the viral growth but also is the candidate for the drug target against viral diseases. Therefore, to study the RNA virus polymerase is very useful strategy for the battle against the diseases of RNA viruses.