Objective: Cloning and nucleotide sequencing of full length cDNA sequence of L segment of Hantavirus strain A9.
Methods: The L segment cDNA of Hantavirus strain A9 was amplified by RT-PCR. PCR products were cloned and sequenced. Full length cDNA clone of the L segment was obtained by subcloning.
Results: The L segment of strain A9 was 6 533 nucleotides in length and encoded a putative L polymerase that was 2 151 amino acids in length. Analysis of nucleotide and deduced amino acid sequences of the L segment of strain A9 showed a close relationship with the other Hantaviruses most notably the 76-118, Cl-1 and Cl-2 strains, with which they shared a 83.8% nucleotide identity. More distant similarity could also be seen with other Hantaviruses. Sequence comparison performed among the RNA-dependent RNA polymerases of 27 negative stranded RNA viruses revealed that the same existence of six conserved regions and several strictly conserved residues located at the deduced amino acid sequence of A9 L segment.
Conclusions: The nucleotide sequence of L segment of strain A9 was similar to other Hantavirus L segments. Deduced amino acid sequence of A9 L segment shares 6 conserved regions with other RNA virus RNA polymerase. The conserved residues in these polymerases and their possible functions in light of the available structural information have been discussed.