biostudies-literatureUnknown285(22)Wunderlich KDespite their close phylogenetic relationship, natural intertypic reassortants between influenza A (FluA) and B (FluB) viruses have not been described. Inefficient polymerase assembly of the three polymerase subunits may contribute to this incompatibility, especially because the known protein-protein interaction domains, including the PA-binding domain of PB1, are highly conserved for each virus type. Here we show that substitution of the FluA PA-binding domain (PB1-A(1-25)) with that of FluB (PB1-B(1-25)) is accompanied by reduced polymerase activity and viral growth of FluA. Consistent with these findings, surface plasmon resonance spectroscopy measurements revealed that PA of FluA exhibits impaired affinity to biotinylated PB1-B(1-25) peptides. PA of FluB showed no detectable affinity tThe Journal of biological chemistry16704-12https://www.ebi.ac.uk/biostudies/studies/S-EPMC2878059biostudies-literatureLimited compatibility of polymerase subunit interactions in influenza A and B viruses.PMC2878059Wolff TSchwemmle MWunderlich KJuozapaitis MMayer DZohner AManz BGotz VMartin AfalseLimited compatibility of polymerase subunit interactions in influenza A and B viruses.Despite their close phylogenetic relationship, natural intertypic reassortants between influenza A (FluA) and B (FluB) viruses have not been described. Inefficient polymerase assembly of the three polymerase subunits may contribute to this incompatibility, especially because the known protein-protein interaction domains, including the PA-binding domain of PB1, are highly conserved for each virus type. Here we show that substitution of the FluA PA-binding domain (PB1-A(1-25)) with that of FluB (PB1-B(1-25)) is accompanied by reduced polymerase activity and viral growth of FluA. Consistent with these findings, surface plasmon resonance spectroscopy measurements revealed that PA of FluA exhibits impaired affinity to biotinylated PB1-B(1-25) peptides. PA of FluB showed no detectable affinity t2010-01-01T00:00:00Z2010 May2026-05-05T02:43:48.442Z2019-03-27T00:31:11ZS-EPMC28780592036375210.1074/jbc.M110.10253310.1074/jbc.m110.102533