PMID: 19177346

Authors:

Piotrowski Y, Hansen G, Boomaars-van der Zanden AL, Snijder EJ, Gorbalenya AE, Hilgenfeld R

Title:

Crystal structures of the X-domains of a Group-1 and a Group-3 coronavirus reveal that ADP-ribose-binding may not be a conserved property.

Journal:

Protein Sci. 2009 Jan;18(1):6-16.

Abstract:

The polyproteins of coronaviruses are cleaved by viral proteases into at least 15 nonstructural proteins (Nsps). Consisting of five domains, Nsp3 is the largest of these (180-210 kDa). Among these domains, the so-called X-domain is believed to act as ADP-ribose-1''-phosphate phosphatase or to bind poly(ADP-ribose). However, here we show that the X-domain of Infectious Bronchitis Virus (strain Beaudette), a Group-3 coronavirus, fails to bind ADP-ribose. This is explained on the basis of the crystal structure of the protein, determined at two different pH values. For comparison, we also describe the crystal structure of the homologous X-domain from Human Coronavirus 229E, a Group-1 coronavirus, which does bind ADP-ribose.