2h85

From Proteopedia

Revision as of 15:13, 20 March 2008

Crystal Structure of Nsp 15 from SARS

Overview

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.

About this Structure

2H85 is a Single protein structure of sequence from Human sars coronavirus. Full crystallographic information is available from OCA.

Reference

Crystal structure and mechanistic determinants of SARS coronavirus nonstructural protein 15 define an endoribonuclease family., Ricagno S, Egloff MP, Ulferts R, Coutard B, Nurizzo D, Campanacci V, Cambillau C, Ziebuhr J, Canard B, Proc Natl Acad Sci U S A. 2006 Aug 8;103(32):11892-7. Epub 2006 Aug 1. PMID:16882730

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