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.
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.
authors.affiliation: Institute of Biochemistry, Center for Structural and Cell Biology in Medicine, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany.
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Piotrowski
authors.forename: Guido
authors.initials: G
authors.lastname: Hansen
authors.forename: A Linda
authors.initials: AL
authors.lastname: Boomaars-van der Zanden
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Snijder
authors.forename: Alexander E
authors.initials: AE
authors.lastname: Gorbalenya
authors.forename: Rolf
authors.initials: R
authors.lastname: Hilgenfeld
mesh_terms: D000246:Adenosine Diphosphate Ribose / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism*; D000595:Amino Acid Sequence; D028941:Coronavirus 229E, Human / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D018360:Crystallography, X-Ray; D001351:Infectious bronchitis virus / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010744:Phosphoric Monoester Hydrolases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding / Q000502:physiology; D011487:Protein Conformation; D045473:Severe acute respiratory syndrome-related coronavirus / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017361:Viral Nonstructural Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: C496852:ADP-ribose 1''-phosphate; D017361:Viral Nonstructural Proteins; D000246:Adenosine Diphosphate Ribose; D010744:Phosphoric Monoester Hydrolases