Potential virulence determinants in terminal regions of variola smallpox virus genome

Nature. 1993 Dec;366(6457):748-51. doi: 10.1038/366748a0.


Smallpox eradication culminated the most successful antimicrobial campaign in medical history. To characterize further the linear double-stranded DNA genome of the aetiological agent of smallpox, we have determined the entire nucleotide sequence of the highly virulent variola major virus, strain Bangladesh-1975 (VAR-BSH; 186,102 base pairs, 33.7% G + C; Genbank accession number, L22579). Here we highlight features of the molecule and focus on a few of the 187 putative proteins that probably contribute to pathogenicity and virus host-range properties. One hundred and fifty proteins were markedly similar to those of vaccinia virus (smallpox vaccine), for which a complete sequence has been reported for strain Copenhagen (VAC-CPN; 191,636 base pairs, 33.3% G + C). The remaining 37 proteins reflected variola-specific sequences or open reading frame divergences for variant proteins, which are often truncated or elongated compared with their vaccinia counterparts.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • DNA, Viral / genetics*
  • Genome, Viral*
  • Humans
  • Molecular Sequence Data
  • Restriction Mapping
  • Sequence Homology, Amino Acid
  • Sequence Homology, Nucleic Acid
  • Vaccinia virus / genetics
  • Variola virus / genetics
  • Variola virus / pathogenicity*
  • Viral Proteins / physiology
  • Virulence


  • DNA, Viral
  • Viral Proteins

Associated data

  • GENBANK/L22579
  • GENBANK/M22812
  • GENBANK/M24218
  • GENBANK/M35027