Comparison and analysis of sequences and structures of hemagglutinins from Influenza A Virus: a minireview

Abstract

Influenza is one of the most widespread diseases in the world. The interest in Avian Influenza Virus has been increasing through the last decade because of greater than ever possibility of a pandemic outbreak. Influenza virus belongs to the Orthomyxoviridae family, which is characterized by a high variety of hemagglutinin and neuraminidase in different subtypes. Hemagglutinin has two very important sites on its surface: receptor binding site and cleavage site. In this study, we compare sequences and structures of various hemagglutinins. Emphasis was put on potential sites of mutations in functionally important domains. The possibility of adaptation of different types of influenza virus to become a pandemic strain was also evaluated. More than 50 different hemagglutinins subtypes were analyzed and compared, pointing out changes in two essential aforementioned sites. In conclusion, H9 hemagglutinin has a high potential to become a Highly Pathogenic Avian Influenza (HPAI) strain. However, H13 should also be observed because it possesses features which could result in an increase of pathogenicity