Block deletions in the neuraminidase genes from some influenza A viruses of the N1 subtype

Abstract

Nucleotide sequences of the 3′ end of the neuraminidase gene from 12 influenza A strains of the N1 subtype show deletions of 33 to 48 nucleotides in four strains isolated from 1933 to 1935. The deletions correlate with the greater mobility of RNA segment 6 (NA gene) from some N1 viruses on denaturing polyacrylamide gel electrophoresis. Amino acid compositions of tryptic peptides isolated from the neuraminidase of A/Bellamy/42 show that the deletions shorten the proteins by 11 to 16 amino acids.