has role has_role has role gene as virulence factor in pathogen has role has_role has role Influenza A virus (A/Puerto Rico/8/1934(H1N1)) protein-coding gene of Influenza A virus (A/Puerto Rico/8/1934(H1N1)) PB1 20120703 211044 956534 Bin Zhao, Oliver He FLUAVs2gp1 NCBI-supplied PMID: 6281731; 18182088; 18660801; 19461581; 21837415 WEB: http://www.ncbi.nlm.nih.gov/gene polymerase 1 protein-coding 4833 MUTATION: mutations eliminating expression of PB1F2 without afffecting the PB1 open reading frame were attenuating following intranasal inoculation [PMID:16873254]. virulence factor gene role