PROLINE-138 IS ESSENTIAL FOR THE ASSEMBLY OF HEPATITIS-B VIRUS CORE PROTEIN

In small RNA viruses, arm-like segments located at the N or C termini have been suggested as mediators in the assembly of the capsid protein s. In many cases the arms of several subunits converge at a common poi nt (the symmetry axis). Recent advances in studies of the hepatitis B virus (HBV) core protein attest the convergence of the segments preced ing the protamine region, around the symmetry axis, where five or six HBc protein subunits converge. We report a mutation study of the regio n that we have suggested forms an armlike structure, which reveals tha t a single mutation, Pro-1 38 --> Gly, prevents the full-length HBV co re protein self-assembling into particles.