A comprehensive list of the Bunyavirales replication promoters reveals a unique promoter structure in Nairoviridae differing from other virus families

The Bunyavirales, a diverse order of viruses, infect various hosts, posing a notable public health threat. Featuring tri-segmented negative-sense RNA genomes, the order's major families exhibit replication promoters at their 5′ and 3′ ends. Understanding how viral polymerases initiate RNA synthesis through these promoters is vital for comprehending replication, pathogenesis, and antiviral development. Using public sequence data, the authors compiled a comprehensive list of bunyavirus replication promoters, revealing distinctive patterns in the 40-nucleotide segments at both ends of the genome. Particularly, the Nairoviridae family, housing the highly pathogenic Crimean-Congo hemorrhagic fever virus, showcases a unique GC-rich promoter structure not found in other families. The nucleotide variation in the promoter region of the Nairoviral L segment differed from that of the M and S segments. Specifically, a lower abundance of G and C was observed at the 5′ and 3′ ends, respectively. This distinction may relate to Nairoviridae's larger genome size, potentially granting pathogenic advantages. The provided replication promoter list is a valuable tool for predicting bunyavirus family-specific replication mechanisms.
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