6N9Y

Atomic structure of Non-Structural protein 1 of bluetongue virus

Summary for 6N9Y

• Entry DOI: 10.2210/pdb6n9y/pdb
• EMDB information: 0383
• Descriptor: Non-structural protein 1 (1 entity in total)
• Functional Keywords: bluetongue virus non-structural protein 1, viral protein
• Biological source: Bluetongue virus 23
• Total number of polymer chains: 1
• Total formula weight: 64554.98

Authors

Kerviel, A.,Ge, P.,Lai, M.,Jih, J.,Boyce, M.,Zhang, X.,Zhou, Z.H.,Roy, P. (deposition date: 2018-12-04, release date: 2019-03-13, Last modification date: 2024-03-20)

Primary citation

Kerviel, A.,Ge, P.,Lai, M.,Jih, J.,Boyce, M.,Zhang, X.,Zhou, Z.H.,Roy, P.
Atomic structure of the translation regulatory protein NS1 of bluetongue virus.
Nat Microbiol, 4:837-845, 2019

PubMed Abstract: Bluetongue virus (BTV) non-structural protein 1 (NS1) regulates viral protein synthesis and exists as tubular and non-tubular forms in infected cells, but how tubules assemble and how protein synthesis is regulated are unknown. Here, we report near-atomic resolution structures of two NS1 tubular forms determined by cryo-electron microscopy. The two tubular forms are different helical assemblies of the same NS1 monomer, consisting of an amino-terminal foot, a head and body domains connected to an extended carboxy-terminal arm, which wraps atop the head domain of another NS1 subunit through hydrophobic interactions. Deletion of the C terminus prevents tubule formation but not viral replication, suggesting an active non-tubular form. Two zinc-finger-like motifs are present in each NS1 monomer, and tubules are disrupted by divalent cation chelation and restored by cation addition, including Zn, suggesting a regulatory role of divalent cations in tubule formation. In vitro luciferase assays show that the NS1 non-tubular form upregulates BTV mRNA translation, whereas zinc-finger disruption decreases viral mRNA translation, tubule formation and virus replication, confirming a functional role for the zinc-fingers. Thus, the non-tubular form of NS1 is sufficient for viral protein synthesis and infectious virus replication, and the regulatory mechanism involved operates through divalent cation-dependent conversion between the non-tubular and tubular forms.

PubMed: 30778144
DOI: 10.1038/s41564-019-0369-x

Experimental method

ELECTRON MICROSCOPY (4 Å)