7F0S

A crystal structure of alphavirus nonstructural protein 4 (nsP4) reveals an intrinsically 1dynamic RNA-dependent RNA polymerase

Summary for 7F0S

• Entry DOI: 10.2210/pdb7f0s/pdb
• Descriptor: RNA-directed RNA polymerase nsP4 (2 entities in total)
• Functional Keywords: rna dependent rna polymerase, rna directed rna polymerase, rdrp, alphavirus, nsp4, nonstructural protein 4, transferase
• Biological source: Ross river virus (strain T48) (RRV); More
• Total number of polymer chains: 1
• Total formula weight: 54224.84

Authors

Tan, Y.B.,Luo, D. (deposition date: 2021-06-06, release date: 2022-02-16, Last modification date: 2024-05-29)

Primary citation

Tan, Y.B.,Lello, L.S.,Liu, X.,Law, Y.S.,Kang, C.,Lescar, J.,Zheng, J.,Merits, A.,Luo, D.
Crystal structures of alphavirus nonstructural protein 4 (nsP4) reveal an intrinsically dynamic RNA-dependent RNA polymerase fold.
Nucleic Acids Res., 50:1000-1016, 2022

PubMed Abstract: Alphaviruses such as Ross River virus (RRV), chikungunya virus (CHIKV), Sindbis virus (SINV), and Venezuelan equine encephalitis virus (VEEV) are mosquito-borne pathogens that can cause arthritis or encephalitis diseases. Nonstructural protein 4 (nsP4) of alphaviruses possesses RNA-dependent RNA polymerase (RdRp) activity essential for viral RNA replication. No 3D structure has been available for nsP4 of any alphaviruses despite its importance for understanding alphaviral RNA replication and for the design of antiviral drugs. Here, we report crystal structures of the RdRp domain of nsP4 from both RRV and SINV determined at resolutions of 2.6 Å and 1.9 Å. The structure of the alphavirus RdRp domain appears most closely related to RdRps from pestiviruses, noroviruses, and picornaviruses. Hydrogen-deuterium exchange mass spectrometry (HDX-MS) and nuclear magnetic resonance (NMR) methods showed that in solution, nsP4 is highly dynamic with an intrinsically disordered N-terminal domain. Both full-length nsP4 and the RdRp domain were capable to catalyze RNA polymerization. Structure-guided mutagenesis using a trans-replicase system identified nsP4 regions critical for viral RNA replication.

PubMed: 35037043
DOI: 10.1093/nar/gkab1302

Experimental method

X-RAY DIFFRACTION (2.6 Å)