tetano
Editor, Senior Moderator
J Virol. 2011 Sep 28. [Epub ahead of print]
Targeting of the influenza A virus polymerase PB1-PB2 interface indicates strain-specific assembly differences.
Reuther P, M?nz B, Brunotte L, Schwemmle M, Wunderlich K.
Source
Department of Virology, Institute for Medical Microbiology and Hygiene, University of Freiburg, Germany.
Abstract
Assembly of the heterotrimeric influenza polymerase complex from the individual subunits PB1, PA and PB2 is a prerequisite for viral replication. The conserved protein-protein interaction sites have been suggested as potential drug targets. To characterize the PB1-PB2 interface, we fused the PB1-binding domain of PB2 to GFP (PB2(1-37)-GFP) and determined its competitive inhibitory effect on the polymerase activity of influenza A virus strains. Co-expression of PB2(1-37)-GFP in a polymerase reconstitution system led to substantial inhibition of the polymerase of A/WSN/33 (H1N1). Surprisingly, polymerases of other strains including A/SC35M (H7N7), A/Puerto Rico/8/34 (H1N1), A/Hamburg/4/2009 (H1N1), and A/Thailand/1(KAN-1)/2004 (H5N1) showed various degrees of resistance. Individual exchange of polymerase subunits and the nucleoprotein between the sensitive WSN and the insensitive SC35M polymerase mapped the resistance to both PB1 and PA of SC35M. While PB2(1-37)-GFP bound equally well to PB1 of both virus strains, PB1/PA dimers of SC35M showed impaired binding compared to PB1/PA dimers of WSN. The use of PA(SC35M/WSN) chimeras revealed that the reduced affinity of the SC35M PB1/PA dimer was mediated by the N-terminal 277 amino acids of PA. Based on these observations we speculate that the PB1/PA dimer formation of resistant polymerases shields the PB2(1-37) binding site, whereas sensitive polymerases allow this interaction, suggesting different assembly strategies of the trimeric polymerase complex between different influenza A virus strains.
PMID:
21957294
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/21957294
Targeting of the influenza A virus polymerase PB1-PB2 interface indicates strain-specific assembly differences.
Reuther P, M?nz B, Brunotte L, Schwemmle M, Wunderlich K.
Source
Department of Virology, Institute for Medical Microbiology and Hygiene, University of Freiburg, Germany.
Abstract
Assembly of the heterotrimeric influenza polymerase complex from the individual subunits PB1, PA and PB2 is a prerequisite for viral replication. The conserved protein-protein interaction sites have been suggested as potential drug targets. To characterize the PB1-PB2 interface, we fused the PB1-binding domain of PB2 to GFP (PB2(1-37)-GFP) and determined its competitive inhibitory effect on the polymerase activity of influenza A virus strains. Co-expression of PB2(1-37)-GFP in a polymerase reconstitution system led to substantial inhibition of the polymerase of A/WSN/33 (H1N1). Surprisingly, polymerases of other strains including A/SC35M (H7N7), A/Puerto Rico/8/34 (H1N1), A/Hamburg/4/2009 (H1N1), and A/Thailand/1(KAN-1)/2004 (H5N1) showed various degrees of resistance. Individual exchange of polymerase subunits and the nucleoprotein between the sensitive WSN and the insensitive SC35M polymerase mapped the resistance to both PB1 and PA of SC35M. While PB2(1-37)-GFP bound equally well to PB1 of both virus strains, PB1/PA dimers of SC35M showed impaired binding compared to PB1/PA dimers of WSN. The use of PA(SC35M/WSN) chimeras revealed that the reduced affinity of the SC35M PB1/PA dimer was mediated by the N-terminal 277 amino acids of PA. Based on these observations we speculate that the PB1/PA dimer formation of resistant polymerases shields the PB2(1-37) binding site, whereas sensitive polymerases allow this interaction, suggesting different assembly strategies of the trimeric polymerase complex between different influenza A virus strains.
PMID:
21957294
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/21957294