M gene translation product (Influenza A virus (strain A/Puerto Rico/8/1934 H1N1)) influenzavirus matrix protein 2 matrix protein 2 (Influenza A virus (strain A/Puerto Rico/8/1934 H1N1)) PR:P06821 UniProtKB:P06821 M2 (Influenza A virus (strain A/Puerto Rico/8/1934 H1N1)) Category=organism-sequence. Requested by=IEDB. Requested by=ImmPort. M/iso:M2 (I34A1) protein proton channel protein M2 (Influenza A virus (strain A/Puerto Rico/8/1934 H1N1)) An influenzavirus matrix protein 2 that is encoded in the genome of the H1N1 strain A/Puerto Rico/8/1934.