[Characteristic analysis of E protein genes of new strains of tick-borne encephalitis virus isolated from China].
In order to determine the characteristics and genotypes of E protein genes of tick-borne encephalitis (TBE) virus strains DXAL-5, 12,13,16,18, 21 isolated from Ixodes persulcatus in the Northeast of China, cDNA synthesis of E protein genes of the six DXAL strains was performed using RT-PCR, and the E protein genes were cloned and sequenced. The results showed that the nucleotide sequence of E protein gene of the six DXAL strains was 1488 bp in length respectively and the length of predicted protein was 496 aa respectively. Sequence comparison of E protein genes among the six DXAL strains and the reference TBE virus strains showed that the six DXAL strains were more homologous to Far Eastern subtype strains than to Siberian subtype strains or European subtype strains. And the majority of subtype-determining amino acid sites of the six DXAL strains belonged to TBE virus Far Eastern subtype. Phylogenetic analysis of protein E showed that the six DXAL strains were all within the clade containing Far Eastern subtype strains. The new strains had higher identities and closer phylogenetic relationships with Senzhang strain, so we speculate that this vaccine strain still have good protection against the new TBE virus isolates. In the A, B and C antigenic domains of protein E, the six DXAL strains had different degrees of amino acid changes. These mutations were likely to affect the function of E protein.
Chen
Lu-Fei
LF
Institute for Viral Disease Control and Prevention, Heilongjiang Provincial Center for Disease Prevention and Control, Harbin 150030, Heilongjiang, China. hljlfc@163.com
Liu
Yan-Cheng
YC
Chen
Shu-Hong
SH
Hui
Shan
S
Li
Ji-Hong
JH
Xu
Jun
J
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002681:China; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004669:Encephalitis Viruses, Tick-Borne / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D051379:Mice; D008969:Molecular Sequence Data; D010802:Phylogeny; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D014759:Viral Envelope Proteins / Q000737:chemistry / Q000235:genetics*
D018076:DNA, Complementary; D014759:Viral Envelope Proteins