Study of HCRSV as nano-materials and structural study of dsRNA recognition by influenza virus A NS 1

Abstract

<P>THE STUDIES IN THIS THESIS WERE MAINLY INVOLVED IN STRUCTURES OF A VIRUS (HCRSV) AND A VIRAL PROTEIN (NS1A). HIBISCUS CHLOROTIC RINGSPOT VIRUS (HCRSV) IS A POSITIVE SENSE, SINGLE-STRANDED RNA VIRUS BELONGING TO CARMOVIRUS GENUS. HCRSV WAS PURIFIED AND CRYSTALLIZED. THE STRUCTURE OF HCRSV, DETERMINED AT 3.2 ANGSTROM, SHOWED THAT HCRSV USE BETA-ANNULUS AND CA2+ MEDIATION TO STABILIZE ITS CAPSIDS. HCRSV WAS ALSO TRIED TO DEVELOP INTO A MODEL AS VIRUS-BASED NANO-MATERIAL. INFLUENZA A VIRUS NS1A SHIELDS THE VIRUSE AGAINST HOST DEFENSE AS AN IMMUNOSUPPRESSOR. THE COMPLEX CRYSTAL STRUCTURE OF NS1A RNA BINDING DOMAIN (RBD) WITH DSRNA REVEALED THAT NS1A RBD FORMS A DIMERIC SIX-HELICAL FOLD AND USED A DIMERIC ANTI-PARALLEL HELICES TO RECOGNIZE THE MAJOR GROOVE OF THE DSRNA AS A SEQUENCE-INDEPENDENT MODE. THE SIGNIFICANT CONFORMATIONAL CHANGE OF RESIDUE R38 BEFORE AND AFTER NS1A RBD BINDING TO DSRNA INDICATED THAT R38 PLAYED A KEY ROLE FOR DSRNA BINDING.</P>