Domains of human respiratory syncytial virus P protein essential for homodimerization and for binding to N and NS1 protein.

In this report we used the two-hybrid technique to test for binding among human respiratory syncytial virus (HRSV) proteins involved in the control of viral replication. Besides the expected positive interactions for the nucleoprotein (N) with itself and the phosphoprotein (P), our results also demonstrated P-P interaction and P-NS1 binding. However, no interactions have been detected for the matrix protein M, the M2-1 and the M2-2 protein neither with each other nor in combination with the phosphoprotein P, the nucleoprotein N or the non-structural protein NS1. While the N-P interaction was abolished by N- and C-terminal deletions of both partners, C-terminal deletion mutants of P were still able to form homodimers. In contrast, the C-terminal region of P turned out to be essential for binding of NS1. N-N interaction was disrupted by any of the N- and C-terminal deletions.