The base pairs of monkeypox virus core genome were 196858 bp(MPXV-ZAI) linear double-stranded DNA molecule, which formed a single-stranded hairpin structure at both ends. Each end of the genome contains an identical but opposite 6379bp terminal inverted repeat, similar to that of other poxviruses, including a predicted telomeric resolution sequence and a short tandem repeat. Computer aided analysis confirmed that the virus genome contained 190 open reading frames containing ≥60 amino acid residues. Four of them are located in the terminal inverted repeat. At present, the function and expression status of most of its genes are not clear. MPXV contains known orthopoxvirus essential genes, but only a subset of immune regulatory genes and host-wide genes.
Comparing the genomes of monkeypox virus and smallpox virus, most of the genes encoding important replicases and structural proteins in the central region of the genome have high homology, while most of the genes encoding virulence and host tropism are located at both ends of the genome, showing high gene heterogeneity. Sequence comparisons confirm that MPXV is a unique orthopoxvirus that is not a direct ancestor or descendant of variola virus, the causative agent of smallpox.
The content of guanine (G) + cytosine (C) in monkeypox virus genome is very low, about 33%, and 20 nucleic acid fragments can be obtained from poxvirus degraded by Hind III endonuctase. The genome can encode a variety of enzymes needed for viral replication, so the virus can replicate independently.