title: The pre-S region of hepadnavirus envelope proteins.
mesh_terms: D000595:Amino Acid Sequence; D005814:Genes, Viral; D006514:Hepatitis B Surface Antigens / Q000235:genetics; D006518:Hepatitis Viruses / Q000235:genetics* / Q000276:immunology; D008969:Molecular Sequence Data; D011498:Protein Precursors / Q000235:genetics / Q000276:immunology; D014759:Viral Envelope Proteins / Q000235:genetics* / Q000276:immunology; D014779:Virus Replication
chemical_list: D006514:Hepatitis B Surface Antigens; D011498:Protein Precursors; D014759:Viral Envelope Proteins; C050806:presurface protein 1, hepatitis B surface antigen; C050807:presurface protein 2, hepatitis B surface antigen