Terminal Region Sequence Variations in Variola Virus DNA

Abstract

Genome DNA terminal region sequences were determined for a Brazilian alastrim variola minor virus strain Garcia-1966 that was associated with an 0.8% case-fatality rate and African smallpox strains Congo-1970 and Somalia-1977 associated with variola major (9.6%) and minor (0.4%) mortality rates, respectively. A base sequence identity of> or = 98.8% was determined after aligning 30 kb of the left- or right-end region sequences with cognate sequences previously determined for Asian variola major strains India-1967 (31% death rate) and Bangladesh-1975 (18.5% death rate). The deduced amino acid sequences of putative proteins of > or = 65 amino acids also showed relatively high identity, although the Asian and African viruses were clearly more related to each other than to alastrim virus. Alastrim virus contained only 10 of 70 proteins that were 100% identical to homologs in Asian strains, and 7 alastrim-specific proteins were noted.

Identification of Hot Spots in the Variola Virus Complement Inhibitor (SPICE) for Human Complement Regulation

“…Like other viral complement regulators, it is formed by four units of CCP domains joined together by linkers of four amino acid residues. Interestingly, SPICE differs from the vaccinia virus complement control protein (VCP) by only 11 amino acids (27,49), which are scattered throughout CCP 2, CCP 3, and CCP 4 domains of the molecule. Despite the minimum difference between the two proteins, SPICE was found to be significantly more active than VCP in inactivating the human complement (43), a finding which is intriguing because variola virus is much more virulent than vaccinia virus.…”

Variola virus immune evasion design: Expression of a highly efficient inhibitor of human complement

“…Our studies concern CRPs encoded in the terminal regions of orthopoxviruses, where proteins important in immune modulation and virulence are encoded (4,7,13,14). Some virally encoded CRPs are similar in structure and function to mammalian CRPs (15).…”

Identifying and Quantifying Genotypes in Polyclonal Infections due to Single Species

“…For Mycobacterium tuberculosis , examples include variation in the tandem repeats within IS 6110 ( 20 ), variable numbers of tandem repeats (VNTRs) ( 21 ), and genomic deletions ( 22 ). For select agents, examples include variation in VNTRs (multiple locus VNTR analysis) in Bacillus anthracis ( 23 , 24 ), similar differences in Yersinia pestis ( 25 ), and insertions, deletions, and variation in the inverted terminal repeat region and the coding region of the smallpox virus ( 26 , 27 ) (Table 4). …”