MUTATIONAL ANALYSIS OF THE INFLUENZA-VIRUS-A VICTORIA 3/75 PA PROTEIN- STUDIES OF INTERACTION WITH PB1 PROTEIN AND IDENTIFICATION OF A DOMINANT-NEGATIVE MUTANT/
T. Zurcher et al., MUTATIONAL ANALYSIS OF THE INFLUENZA-VIRUS-A VICTORIA 3/75 PA PROTEIN- STUDIES OF INTERACTION WITH PB1 PROTEIN AND IDENTIFICATION OF A DOMINANT-NEGATIVE MUTANT/, Journal of General Virology, 77, 1996, pp. 1745-1749
The RNA polymerase activity and PB1 binding of influenza virus PA muta
nts were studied using an in vivo-reconstituted polymerase assay and a
two hybrid system, Deletions covering the whole PA protein abolished
polymerase activity, but the deletion of the 154 N-terminal amino acid
s allowed PB1 binding, indicating that the PA protein N terminus is no
t absolutely required for this interaction, Further internal or C-term
inal deletions abolished PB1 interaction, suggesting that most of the
protein is involved in this association, As a novel finding we showed
that a single amino acid insertion mutant, PAI672, was responsible for
a temperature-sensitive phenotype, Mutant PAS509, which had a serine
insertion at position 509, bound to PB1 like wild-type PA but did not
show any polymerase activity, Over-expression of PAS509 interfered wit
h the polymerase activity of wild-type PA, identifying PAS509 as a dom
inant negative mutant.