Expression, crystallization and preliminary crystallographic study of the C-terminal half of nsp2 from SARS coronavirus.

SARS coronavirus (SARS-CoV) is the aetiological agent of the highly infectious severe acute respiratory syndrome (SARS). To gain a better understanding of SARS-CoV replication and transcription proteins, a preliminary X-ray crystallographic study of the C-terminal domain of SARS-CoV nonstructural protein 2 (nsp2) is reported here. The C-terminal domain of SARS-CoV nsp2 was cloned, overexpressed, purified and crystallized using polyethylene glycol 5000 monomethyl ether as the precipitant; the crystals diffracted to 2.5 Å resolution. The crystals belonged to space group P6(5), with unit-cell parameters a=b=112.8, c=91.1 Å, α=β=90, γ=120°. One molecule is assumed to be present per asymmetric unit, which gives a Matthews coefficient of 2.89 Å3 Da(-1) and a solvent content of 56.2%.