Analysis of the primary structure of segments of the Karelian fever virus genome

: Primary structure of two parts of Karelian fever virus (KFV) genome (29-57 nt and 10507-11591 nt) cloned in recombinant plasmids has been studied and compared with that of Sindbis (HRSP strain) and Ockelbo viruses. Fifty-four nucleotide substitutes were revealed in the sequenced parts of KFV genome including partially 5' and 3'-nontranslated sites ( a total of 1613 nucleotides, or approximately 13.8% of the genome length), in comparison with the Sindbis virus prototype HRSP strain, this being in good correlation with strain variability. Eighteen nucleotide substitutes (96.4% homology) were detected in the NSP1 gene site (60-557 nt) of KFV in comparison with Sindbis virus and only 5 substitutes (98.8% homology) vs. Ockelbo virus. These data on primary structure of KFV genome reliably and unambiguously indicate the appurtenance of this virus to Sindbis-like viruses.