Transient oligomerization of the SARS-CoV N protein--implication for virus ribonucleoprotein packaging.
PLoS One
; 8(5): e65045, 2013.
Article
in En
| MEDLINE
| ID: mdl-23717688
ABSTRACT
The nucleocapsid (N) phosphoprotein of the severe acute respiratory syndrome coronavirus (SARS-CoV) packages the viral genome into a helical ribonucleocapsid and plays a fundamental role during viral self-assembly. The N protein consists of two structural domains interspersed between intrinsically disordered regions and dimerizes through the C-terminal structural domain (CTD). A key activity of the protein is the ability to oligomerize during capsid formation by utilizing the dimer as a building block, but the structural and mechanistic bases of this activity are not well understood. By disulfide trapping technique we measured the amount of transient oligomers of N protein mutants with strategically located cysteine residues and showed that CTD acts as a primary transient oligomerization domain in solution. The data is consistent with the helical oligomer packing model of N protein observed in crystal. A systematic study of the oligomerization behavior revealed that altering the intermolecular electrostatic repulsion through changes in solution salt concentration or phosphorylation-mimicking mutations affects oligomerization propensity. We propose a biophysical mechanism where electrostatic repulsion acts as a switch to regulate N protein oligomerization.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Nucleocapsid Proteins
/
Severe acute respiratory syndrome-related coronavirus
Language:
En
Journal:
PLoS One
Year:
2013
Document type:
Article