New Insights into Structural Disorder in Human Respiratory Syncytial Virus Phosphoprotein and Implications for Binding of Protein Partners.
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ABSTRACT:
SUBMITTER: Pereira N
PROVIDER: S-EPMC5313087 | biostudies-literature | 2017 Feb
REPOSITORIES: biostudies-literature
Publications
New Insights into Structural Disorder in Human Respiratory Syncytial Virus Phosphoprotein and Implications for Binding of Protein Partners.
Pereira Nelson N Cardone Christophe C Lassoued Safa S Galloux Marie M Fix Jenna J Assrir Nadine N Lescop Ewen E Bontems François F Eléouët Jean-François JF Sizun Christina C
The Journal of biological chemistry 20161228 6
Phosphoprotein is the main cofactor of the viral RNA polymerase of <i>Mononegavirales</i> It is involved in multiple interactions that are essential for the polymerase function. Most prominently it positions the polymerase complex onto the nucleocapsid, but also acts as a chaperone for the nucleoprotein. <i>Mononegavirales</i> phosphoproteins lack sequence conservation, but contain all large disordered regions. We show here that N- and C-terminal intrinsically disordered regions account for 80% ...[more]
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Project description:UnlabelledPresently, respiratory syncytial virus (RSV), the main cause of severe respiratory infections in infants, cannot be treated efficiently with antivirals. However, its RNA-dependent polymerase complex offers potential targets for RSV-specific drugs. This includes the recognition of its template, the ribonucleoprotein complex (RNP), consisting of genomic RNA encapsidated by the RSV nucleoprotein, N. This recognition proceeds via interaction between the phosphoprotein P, which is the main polymerase cofactor, and N. The determinant role of the C terminus of P, and more particularly of the last residue, F241, in RNP binding and viral RNA synthesis has been assessed previously. Here, we provide detailed structural insight into this crucial interaction for RSV polymerase activity. We solved the crystallographic structures of complexes between the N-terminal domain of N (N-NTD) and C-terminal peptides of P and characterized binding by biophysical approaches. Our results provide a rationale for the pivotal role of F241, which inserts into a well-defined N-NTD pocket. This primary binding site is completed by transient contacts with upstream P residues outside the pocket. Based on the structural information of the N-NTD:P complex, we identified inhibitors of this interaction, selected by in silico screening of small compounds, that efficiently bind to N and compete with P in vitro. One of the compounds displayed inhibitory activity on RSV replication, thereby strengthening the relevance of N-NTD for structure-based design of RSV-specific antivirals.ImportanceRespiratory syncytial virus (RSV) is a widespread pathogen that is a leading cause of acute lower respiratory infections in infants worldwide. RSV cannot be treated efficiently with antivirals, and no vaccine is presently available, with the development of pediatric vaccines being particularly challenging. Therefore, there is a need for new therapeutic strategies that specifically target RSV. The interaction between the RSV phosphoprotein P and the ribonucleoprotein complex is critical for viral replication. In this study, we identified the main structural determinants of this interaction, and we used them to screen potential inhibitors in silico. We found a family of molecules that were efficient competitors of P in vitro and showed inhibitory activity on RSV replication in cellular assays. These compounds provide a basis for a pharmacophore model that must be improved but that holds promises for the design of new RSV-specific antivirals.
| S-EPMC4621127 | biostudies-literature