3ZFN: Crystal Structure Of Product-like, Processed N-terminal Protease Npro

Npro is a key effector protein of pestiviruses such as bovine viral diarrhea virus and abolishes host cell antiviral defense mechanisms. Synthesized as the N-terminal part of the viral polyprotein, Npro releases itself via an autoproteolytic cleavage, triggering its immunological functions. However, the mechanisms of its proteolytic action and its immune escape were unclear. Here, we present the crystal structures of Npro to 1.25 A resolution. Structures of pre- and postcleavage intermediates identify three catalytically relevant elements. The trapping of the putative catalytic water reveals its distinct roles as a base, acid, and nucleophile. The presentation of the substrate further explains the enigmatic latency of the protease, ensuring a single in cis cleavage. Additionally, we identified a zinc-free, disulfide-linked conformation of the TRASH motif, an interaction hub of immune factors. The structure opens additional opportunities in utilizing Npro as an autocleaving fusion protein and as a pharmaceutical target.
PDB ID: 3ZFNDownload
MMDB ID: 110024
PDB Deposition Date: 2012/12/12
Updated in MMDB: 2013/06
Experimental Method:
x-ray diffraction
Resolution: 1.5  Å
Source Organism:
Similar Structures:
Biological Unit for 3ZFN: monomeric; determined by author and by software (PISA)
Molecular Components in 3ZFN
Label Count Molecule
Protein (1 molecule)
N-terminal Protease Npro
Molecule annotation
Chemicals (2 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB