4BHH: Crystal Structure Of Tetramer Of La Crosse Virus Nucleoprotein In Complex With Ssrna

The nucleoprotein (NP) of segmented negative-strand RNA viruses such as Orthomyxo-, Arena-, and Bunyaviruses coats the genomic viral RNA and together with the polymerase forms ribonucleoprotein particles (RNPs), which are both the template for replication and transcription and are packaged into new virions. Here we describe the crystal structure of La Crosse Orthobunyavirus NP both RNA free and a tetrameric form with single-stranded RNA bound. La Crosse Orthobunyavirus NP is a largely helical protein with a fold distinct from other bunyavirus genera NPs. It binds 11 RNA nucleotides in the positively charged groove between its two lobes, and hinged N- and C-terminal arms mediate oligomerization, allowing variable protein-protein interface geometry. Oligomerization and RNA binding are mediated by residues conserved in the Orthobunyavirus genus. In the twofold symmetric tetramer, 44 nucleotides bind in a closed ring with sharp bends at the NP-NP interfaces. The RNA is largely inaccessible within a continuous internal groove. Electron microscopy of RNPs released from virions shows them capable of forming a hierarchy of more or less compact irregular helical structures. We discuss how the planar, tetrameric NP-RNA structure might relate to a polar filament that upon supercoiling could be packaged into virions. This work gives insight into the RNA encapsidation and protection function of bunyavirus NP, but also highlights the need for dynamic rearrangements of the RNP to give the polymerase access to the template RNA.
PDB ID: 4BHHDownload
MMDB ID: 109353
PDB Deposition Date: 2013/4/3
Updated in MMDB: 2013/05
Experimental Method:
x-ray diffraction
Resolution: 3.4  Å
Source Organism:
synthetic construct
Similar Structures:
Biological Unit for 4BHH: pentameric; determined by author and by software (PISA)
Molecular Components in 4BHH
Label Count Molecule
Proteins (4 molecules)
Molecule annotation
Nucleotide(1 molecule)
Poly-uridine 45-mer
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB