Figure 1. The external (A) and interior (B) structures of
hantaviruses with three genomic RNA segments (L, M, and S).
Like most members of Bunyavirales , hantaviruses genome
encompasses large (L), medium (M), and small (S) single-stranded
negative-sense RNA (−ssRNA) segments, consisting of about 10,000−15,000
nucleotides in total (Figure 2 ).33 The L
segment encodes RdRp that mediates the transcription and replication of
viral genomic RNA. The M segment encodes a glycoprotein precursor (GPC),
which is co-translated and cleaved by host cell signal peptidases to Gn
and Gc.34 Gn and Gc bind to cell receptors, regulate
immune responses, and induce protective antibodies.4The S segment encodes the N protein, which binds to and protects the
viral RNA molecules. The S segment of some orthohantaviruses(e.g., ANDV, PUUV, SNV, TULV, and LANV) encodes a nonstructural protein
(NS), which inhibit the production of interferon in host
cells.35
The terminal untranslated region (UTR) sequences of the genomic segments
of hantaviruses are highly conserved and complementary. They form stalk
structures and participate in the replication and transcription of viral
genomic RNA (vRNA).36,37