Frequency of a nucleotide overhang at the 5’ end of hemorrhagic fever mammarenavirus genomes in public sequence data

Mammarenaviruses, such as Lassa virus and South American hemorrhagic fever (SAHF) virus, cause severe hemorrhagic fevers in humans, and pose major threats to public health. Mammarenaviruses consist of a bi-segmented negative-sense RNA genome in which the 5’ and 3’ ends form complementary strands that serve as a replication promoter. Some mammarenaviruses have a nucleotide overhang at the 5’ genome end. By examining the complementarity of 5’ and 3’ genome ends using public mammarenavirus genome sequences, we found that the 5’ guanine overhang (5’-G overhang) was present more frequently in Lassa and SAHF viruses than in other viruses. The 5’-G overhang in the Lassa and SAHF virus sequences was found to be restricted to the L and S segments, respectively. If the genome end sequence data in the public database are accurate, the 5’-G overhang may be related to the high pathogenicity of mammarenaviruses in humans.