♦Frameshifted structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.90) (Coat protein) (C)
♦ Precursor of protein E3/E2 (p62) (pE2)
♦ Assembly protein E3
♦ Spike glycoprotein E2 (E2 envelope glycoprotein)
♦ Protein TF]

Not Available

MNRGFFNMLGRRPFPAPTAMWRPRRRRQAAPMPARNGLASQIQQLTTAVSALVIGQATRPQPPRPRPPPRQKKQAPKQPPKPKKPKTQEKKKKQPAKPKP
GKRQRMALKLEADRLFDVKNEDGDVIGHALAMEGKVMKPLHVKGTIDHPVLSKLKFTKSSAYDMEFAQLPVNMRSEAFTYTSEHPEGFYNWHHGAVQYSG
GRFTIPRGVGGRGDSGRPIMDNSGRVVAIVLGGADEGTRTALSVVTWNSKGKTIKTTPEGTEEWSAAPLVTAMCLLGNVSFPCDRPPTCYTREPSRALDI
LEENVNHEAYDTLLNAILRCGSSGRSKRSVIDDFTLTSPYLGTCSYCHHTVPCFSPVKIEQVWDEADDNTIRIQTSAQFGYDQSGAASANKYRYMSLKQD
HTVKEGTMDDIKISTSGPCRRLSYKGYFLLAKCPPGDSVTVSIVSSNSATSCTLARKIKPKFVGREKYDLPPVHGKKIPCTVYDRLKETTAGYITMHRPR
PHAYTSYLEESSGKVYAKPPSGKNITYECKCGDYKTGTVSTRTEITGCTAIKQCVAYKSDQTKWVFNSPDLIRHDDHTAQGKLHLPFKLIPSTCMVPVAH
APNVIHGFKHISLQLDTDHLTLLTTRRLGANPEPTTEWIVGKTVRNFTVDRDGLEYIWGNHEPVRVYAQESAPGDPHGWPHEIVQHYYHRHPVYTILAVA
SATVAMMIGVTVAVLCACKARRECLTPYALAPNAVIPTSLALLCCVRSANAETFTETMSYLWSNSQPFFWVQLCIPLAAFIVLMRCCSCCLPFLSGCRRL
PGEGRRLRTCDHCSKCATDTV

♦Capsid protein: Forms an icosahedral capsid with a T=4 symmetry composed of 240 copies of the capsid protein surrounded by a lipid membrane through which penetrate 80 spikes composed of trimers of E1-E2 heterodimers. Possesses a protease activity that results in its autocatalytic cleavage from the nascent structural protein. Following its self-cleavage, the capsid protein transiently associates with ribosomes, and within several minutes the protein binds to viral RNA and rapidly assembles into icosahedric core particles. The resulting nucleocapsid eventually associates with the cytoplasmic domain of E2 at the cell membrane, leading to budding and formation of mature virions. New virions attach to target cells, and after clathrin-mediated endocytosis their membrane fuses with the host endosomal membrane. This leads to the release of the nucleocapsid into the cytoplasm, followed by an uncoating event necessary for the genomic RNA to become accessible. The uncoating might be triggered by the interaction of capsid proteins with ribosomes. Binding of ribosomes would release the genomic RNA since the same region is genomic RNA-binding and ribosome-binding.
♦ Assembly protein E3: May be a disulfide isomerase that catalyzes the proper folding and disulfide bond formation in pE2/E2. E3 possesses labile disulfide bonds and is in close proximity to E2 throughout the assembly pathway.
♦ Spike glycoprotein E2: Plays an essential role in viral attachment to target host cell, by binding to the cell receptor. Synthesized as a pE2 precursor which is processed by furin at the cell membrane just before virion budding, giving rise to E2-E1 heterodimer. The pE2-E1 heterodimer is stable, whereas E2-E1 is unstable and dissociate at low pH. pE2 is processed at the last step, presumably to avoid E1 fusion activation before its final export to cell surface. E2 C-terminus contains a transitory transmembrane that would be disrupted by palmitoylation, resulting in reorientation of the C-terminal tail from lumenal to cytoplasmic side. This step is critical since E2 C-terminus is involved in budding by interacting with capsid proteins. This release of E2 C-terminus in cytoplasm occurs lately in protein export, and precludes premature assembly of particles at the endoplasmic reticulum membrane.
♦ Protein TF: Plays a role in viral assembly and release.

♦ Capsid protein: Virion . Host cytoplasm . Host cell membrane .
♦ Precursor of protein E3/E2: Virion membrane
♦ Multi-pass membrane protein . Host cell membrane
♦ Multi-pass membrane protein .
♦ Spike glycoprotein E2: Virion membrane
♦ Multi-pass membrane protein . Host cell membrane ,
♦ Multi-pass membrane protein .
♦ Protein TF: Host cell membrane
♦ Single-pass membrane protein . Virion .

DOMAIN 114 264 Peptidase S3.

♦ACT_SITE 141 141 Charge relay system.
♦ ACT_SITE 163 163 Charge relay system.
♦ ACT_SITE 215 215 Charge relay system.