Capsid proteins VP1, VP2, and VP3 form a closed capsid enclosing the viral positive strand RNA genome. All these proteins contain a beta-sheet structure called beta-barrel jelly roll. Together they form an icosahedral capsid (T=3) composed of 60 copies of each VP1, VP2, and VP3, with a diameter of approximately 300 Angstroms. VP1 is situated at the 12 fivefold axes, whereas VP2 and VP3 are located at the quasi-sixfold axes. The naked capsid interacts with the host receptor HAVCR1 to provide virion attachment to and probably entry into the target cell. Capsid proteins VP1, VP2, and VP3 form a closed capsid enclosing the viral positive strand RNA genome. All these proteins contain a beta-sheet structure called beta-barrel jelly roll. Together they form an icosahedral capsid (T=3) composed of 60 copies of each VP1, VP2, and VP3, with a diameter of approximately 300 Angstroms. VP1 is situated at the 12 fivefold axes, whereas VP2 and VP3 are located at the quasi-sixfold axes. The naked capsid interacts with the host receptor HAVCR1 to provide virion attachment to and probably entry into the target cell. Precursor component of immature procapsids that corresponds to an extended form of the structural protein VP1. After maturation, possibly by the host Cathepsin L, the assembly signal 2A is cleaved to give rise to the mature VP1 protein. Homopentamer. Homooligomer. The egress of newly formed virions occurs through an exosome-like mechanism involving endosomal budding of viral capsids into multivesicular bodies. The egress of newly formed virions occurs through an exosome-like mechanism involving endosomal budding of viral capsids into multivesicular bodies. The assembly signal 2A region mediates pentamerization of P1-2A. Late-budding domains (L domains) are short sequence motifs essential for viral particle budding. They recruit proteins of the host ESCRT machinery (Endosomal Sorting Complex Required for Transport) or ESCRT-associated proteins. The genome polyprotein contains two L domains: a tandem of (L)YPX(n)L domain which is known to bind the PDCD6IP/ALIX adaptater protein. Specific enzymatic cleavages by viral protease in vivo yield a variety of precursors and mature proteins. Polyprotein processing intermediates are produced, such as P1-2A which is a functional precursor of the structural proteins, VP0 which is a VP4-VP2 precursor, VP1-2A precursor, 3ABC precursor which is a stable and catalytically active precursor of 3A, 3B and 3C proteins, 3AB and 3CD precursors. The assembly signal 2A is removed from VP1-2A by a host protease, possibly host Cathepsin L. This cleavage occurs over a region of 3 amino-acids probably generating VP1 proteins with heterogeneous C-termini. The assembly signal 2A is removed from VP1-2A by a host protease, possibly host Cathepsin L in naked virions. This cleavage does not occur in enveloped virions. This cleavage occurs over a region of 3 amino-acids probably generating VP1 proteins with heterogeneous C-termini. The need for an intact eIF4G factor for the initiation of translation of HAV results in an inability to shut off host protein synthesis by a mechanism similar to that of other picornaviruses. During infection, enveloped virions (eHAV) are released from cells. These eHAV are cloaked in host-derived membranes and resemble exosomes. The membrane of eHAV is devoid of viral proteins and thus prevents their neutralization by antibodies. eHAV budding is dependent on ESCRT-associated proteins VPS4B and PDCD6IP/ALIX. eHAV are produced and released in the serum and plasma, but not in bile and feces which only contain the naked, nonenveloped virions. It is likely that eHAV also use HAVCR1 as a functional receptor to infect cells, an evolutionary trait that may enhance HAV infectivity. Belongs to the picornaviridae polyprotein family.