Characterization of a temperature-sensitive mutant in the RNA polymerase PB2 subunit gene of influenza A/WSN/33 virus.
The temperature-sensitive mutant ts-1 of influenza virus A/WSN/33 carries mutations in the gene encoding RNA polymerase PB2 subunit. Effect of temperature on various steps of viral RNA synthesis was examined using disrupted virions of ts-1 mutant. The initiation of RNA synthesis with dinucleotide ApG primer was not affected by elevated temperature, whereas that with primer RNA containing 5'-terminal cap-1 structure was temperature-sensitive. The result supports the previous notion deduced from the UV-crosslinking experiments, that PB2 is involved in the cap-1 dependent initiation of RNA synthesis. In addition, the ts-1 mutant showed a defect in RNA chain elongation. Nucleotide sequence analysis of RNA segment 1 of ts-1 mutant revealed that the amino acid number 417 is essential for the recognition of cap-1 structures and/or the interaction with catalytic unit of the RNA polymerase.
Yamanaka
K
K
Department of Genetics, School of Medicine, Osaka University, Japan.
Ogasawara
N
N
Ueda
M
M
Yoshikawa
H
H
Ishihama
A
A
Nagata
K
K
D000595:Amino Acid Sequence; D001483:Base Sequence; D002478:Cells, Cultured; D003001:Cloning, Molecular; D004252:DNA Mutational Analysis; D004279:DNA, Viral / Q000235:genetics; D012321:DNA-Directed RNA Polymerases / Q000235:genetics*; D005814:Genes, Viral; D009980:Influenza A virus / Q000201:enzymology / Q000235:genetics* / Q000502:physiology; D008969:Molecular Sequence Data; D009154:Mutation; D012367:RNA, Viral / Q000096:biosynthesis / Q000235:genetics; D013696:Temperature; D014158:Transcription, Genetic / Q000502:physiology; D014779:Virus Replication / Q000235:genetics
D004279:DNA, Viral; D012367:RNA, Viral; D012321:DNA-Directed RNA Polymerases