Structural highlights
Function
[NSP2_ROTSR] Involved in genome replication and packaging. Plays a crucial role, together with NSP5, in the formation of virus factories (viroplasms) which are large inclusions in the cytoplasm where replication intermediates are assembled and RNA replication takes place. Displays ssRNA binding, NTPase, RNA triphosphatase (RTPase) and ATP-independent helix-unwinding activity activities. The unwiding activity may prepare and organize plus-strand RNAs for packaging and replication by removing interfering secondary structures. Unlike typical helicases, NSP2 requires neither a divalent cation nor a nucleotide energy source for helix destabilization. The RTPase activity may account for the absence of the 5'-terminal gamma-phosphate on the minus-strands of dsRNA genome segments (By similarity).
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Rotavirus, the major cause of life-threatening infantile gastroenteritis, is a member of the Reoviridae. Although the structures of rotavirus and other members of the Reoviridae have been extensively studied, little is known about the structures of virus-encoded non-structural proteins that are essential for genome replication and packaging. The non-structural protein NSP2 of rotavirus, which exhibits nucleoside triphosphatase, single-stranded RNA binding, and nucleic-acid helix-destabilizing activities, is a major component of viral replicase complexes. We present here the X-ray structure of the functional octamer of NSP2 determined to a resolution of 2.6 A. The NSP2 monomer has two distinct domains. The amino-terminal domain has a new fold. The carboxy-terminal domain resembles the ubiquitous cellular histidine triad (HIT) group of nucleotidyl hydrolases. This structural similarity suggests that the nucleotide-binding site is located inside the cleft between the two domains. Prominent grooves that run diagonally across the doughnut-shaped octamer are probable locations for RNA binding. Several RNA binding sites, resulting from the quaternary organization of NSP2 monomers, may be required for the helix destabilizing activity of NSP2 and its function during genome replication and packaging.
Rotavirus protein involved in genome replication and packaging exhibits a HIT-like fold.,Jayaram H, Taraporewala Z, Patton JT, Prasad BV Nature. 2002 May 16;417(6886):311-5. PMID:12015608[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Jayaram H, Taraporewala Z, Patton JT, Prasad BV. Rotavirus protein involved in genome replication and packaging exhibits a HIT-like fold. Nature. 2002 May 16;417(6886):311-5. PMID:12015608 doi:http://dx.doi.org/10.1038/417311a
