2H85

Crystal Structure of Nsp 15 from SARS

Summary for 2H85

• Entry DOI: 10.2210/pdb2h85/pdb
• Descriptor: Putative orf1ab polyprotein (2 entities in total)
• Functional Keywords: endoribonuclease, sars, rna, nsp, viral protein
• Biological source: SARS coronavirus
• Total number of polymer chains: 1
• Total formula weight: 38570.83

Authors

Ricagno, S.,Egloff, M.P.,Ulferts, R.,Coutard, B.,Nurizzo, D.,Campanacci, V.,Cambillau, C.,Ziebuhr, J.,Canard, B. (deposition date: 2006-06-06, release date: 2006-08-15, Last modification date: 2024-02-14)

Primary citation

Ricagno, S.,Egloff, M.P.,Ulferts, R.,Coutard, B.,Nurizzo, D.,Campanacci, V.,Cambillau, C.,Ziebuhr, J.,Canard, B.
Crystal structure and mechanistic determinants of SARS coronavirus nonstructural protein 15 define an endoribonuclease family.
Proc.Natl.Acad.Sci.Usa, 103:11892-11897, 2006

PubMed Abstract: The approximately 30-kb coronavirus (+)RNA genome is replicated and transcribed by a membrane-bound replicase complex made up of 16 viral nonstructural proteins (nsp) with multiple enzymatic activities. The complex includes an RNA endonuclease, NendoU, that is conserved among nidoviruses but no other RNA virus, making it a genetic marker of this virus order. NendoU (nsp15) is a Mn(2+)-dependent, uridylate-specific enzyme, which leaves 2'-3'-cyclic phosphates 5' to the cleaved bond. Neither biochemical nor sequence homology criteria allow a classification of nsp15 into existing endonuclease families. Here, we report the crystal structure of the severe acute respiratory syndrome coronavirus nsp15 at 2.6-A resolution. Nsp15 exhibits a unique fold and assembles into a toric hexamer with six potentially active, peripheric catalytic sites. The structure and the spatial arrangement of the catalytic residues into an RNase A-like active site define a separate endonuclease family, endoU, and represent another spectacular example of convergent evolution toward an enzymatic function that is critically involved in the coronavirus replication cycle.

PubMed: 16882730
DOI: 10.1073/pnas.0601708103

Experimental method

X-RAY DIFFRACTION (2.6 Å)