Table 14.8 Functions and properties of astrovirus proteins
From: Viruses with Single-Stranded, Positive-Sense RNA Genomes
Protein | Norovirus | Sapovirus | Feline calicivirus | RHDV | Function |
|---|---|---|---|---|---|
Non-structural protein | 37–48 kDa | 32 kDa | 32 kDa | ? kDa | Associates with Golgi vesicles, influences intracellular protein transport |
Non-structural protein | 40–41 kDa | 35 kDa | 36–38 kDa | 37 kDa | NTPase, helicase? essential for transcription and replication |
Non-structural protein | 20–22 kDa | 32 kDa | 30 kDa | 29 kDa | Function unknown; membrane associated? |
Vpg | 16 kDa | 14 kDa | 15.5 kDa | 13 kDa | Covalently linked with the 5′ terminus of RNA, translation initiation |
Protease, 3CLpro | 19 kDa | 14 kDa | 30 kDa | 15 kDa | 3C-like protease, cleavage of precursor proteins |
Polymerase | 57 kDa | 57 kDa | 50 kDa | 58 kDa | RNA-dependent RNA polymerase, transcription, replication |
Capsid protein VP1 | 68 kDa (ORF2) | 60–62 kDa (ORF1) | 60–65 kDa (ORF2) | 60 kDa (ORF1) | Structural protein, dimer, major capsid protein |
Structural protein VP2 | 23–29 kDa (ORF3) | 23–29 kDa (ORF2) | 12 kDa (ORF3) | 10 kDa (ORF2) | Structural protein, RNA binding |