The severe acute respiratory syndrome-coronavirus replicative protein nsp9 is a single-stranded RNA-binding subunit unique in the RNA virus world.
The recently identified etiological agent of the severe acute respiratory syndrome (SARS) belongs to Coronaviridae (CoV), a family of viruses replicating by a poorly understood mechanism. Here, we report the crystal structure at 2.7-A resolution of nsp9, a hitherto uncharacterized subunit of the SARS-CoV replicative polyproteins. We show that SARS-CoV nsp9 is a single-stranded RNA-binding protein displaying a previously unreported, oligosaccharide/oligonucleotide fold-like fold. The presence of this type of protein has not been detected in the replicative complexes of RNA viruses, and its presence may reflect the unique and complex CoV viral replication/transcription machinery.
Egloff
Marie-Pierre
MP
Architecture et Fonction des Macromolécules Biologiques, Unité Mixte de Recherche 6098 Centre National de la Recherche Scientifique and Universités Aix-Marseille I et II, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.
Ferron
François
F
Campanacci
Valérie
V
Longhi
Sonia
S
Rancurel
Corinne
C
Dutartre
Hélène
H
Snijder
Eric J
EJ
Gorbalenya
Alexander E
AE
Cambillau
Christian
C
Canard
Bruno
B
D000595:Amino Acid Sequence; D018360:Crystallography, X-Ray; D004277:DNA, Single-Stranded / Q000378:metabolism*; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D012313:RNA / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D045473:Severe acute respiratory syndrome-related coronavirus / Q000235:genetics* / Q000378:metabolism; D020539:Sequence Analysis, Protein; D045169:Severe Acute Respiratory Syndrome / Q000378:metabolism* / Q000821:virology; D014764:Viral Proteins / Q000235:genetics* / Q000378:metabolism
D004277:DNA, Single-Stranded; D016601:RNA-Binding Proteins; D014764:Viral Proteins; C483945:nsp9 protein, SARS virus; D012313:RNA