Molecular assembly of the influenza virus RNA polymerase: determination of the subunit-subunit contact sites.
Influenza virus RNA polymerase with the subunit structure PB1-PB2-PA is involved in both transcription and replication of the RNA genome. By transfection of various combinations of cDNA encoding wild-type and serial deletion mutants of each P protein subunit and co-immunoprecipitation with subunit-specific antibodies, the subunit-subunit contact sites on all three of the P proteins were determined. Results indicate that binary complexes are formed between PB1-PB2 and PB1-PA but not between PB2-PA. Therefore, we concluded that PB1 is the core subunit for assembly of the virus RNA polymerase. The C-terminal 158 amino acids of PB1 bound to the N-terminal 249 amino acids of PB2, while the N-terminal 140 amino acids of PB1 bound to the C-terminal two-thirds of PA. PB2-PA binding was not detected when they were expressed in the absence of the PB1 subunit.
Toyoda
T
T
Department of Molecular Genetics, National Institute of Genetics, Shizuoka, Japan. ttoyoda@ddbj.nig.ac.jp
Adyshev
D M
DM
Kobayashi
M
M
Iwata
A
A
Ishihama
A
A
D000818:Animals; D001665:Binding Sites; D002461:Cell Line, Transformed; D002522:Chlorocebus aethiops; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D015870:Gene Expression; D009975:Orthomyxoviridae / Q000201:enzymology*; D012324:RNA-Dependent RNA Polymerase; D011817:Rabbits; D017384:Sequence Deletion; D014162:Transfection; D014764:Viral Proteins / Q000378:metabolism*
C061290:PA protein, influenza viruses; C057027:PB2 protein, Influenzavirus A; D014764:Viral Proteins; C077346:influenza virus polymerase basic protein 1; D012324:RNA-Dependent RNA Polymerase; D012321:DNA-Directed RNA Polymerases