3J9D: Atomic Structure Of A Non-enveloped Virus Reveals Ph Sensors For A Coordinated Process Of Cell Entry

Viruses sense environmental cues such as pH to engage in membrane interactions for cell entry during infection, but how nonenveloped viruses sense pH is largely undefined. Here, we report both high- and low-pH structures of bluetongue virus (BTV), which enters cells via a two-stage endosomal process. The receptor-binding protein VP2 possesses a zinc finger that may function to maintain VP2 in a metastable state and a conserved His866, which senses early-endosomal pH. The membrane-penetration protein VP5 has three domains: dagger, unfurling and anchoring. Notably, the beta-meander motif of the anchoring domain contains a histidine cluster that can sense late-endosomal pH and also possesses four putative membrane-interaction elements. Exposing BTV to low pH detaches VP2 and dramatically refolds the dagger and unfurling domains of VP5. Our biochemical and structure-guided-mutagenesis studies support these coordinated pH-sensing mechanisms.
PDB ID: 3J9DDownload
MMDB ID: 134624
PDB Deposition Date: 2015/1/9
Updated in MMDB: 2015/12
Experimental Method:
electron microscopy
Resolution: 3.5  Å
Source Organism:
Similar Structures:
Biological Unit for 3J9D: monomeric; determined by author
Molecular Components in 3J9D
Label Count Molecule
Protein (1 molecule)
Outer Capsid Protein VP2
Molecule annotation
Chemical (1 molecule)
* Click molecule labels to explore molecular sequence information.

Citing MMDB