title: Crystal structure of Epstein-Barr virus protein BCRF1, a homolog of cellular interleukin-10.
abstract: The crystal structure of Epstein-Barr virus protein BCRF1, an analog of cellular interleukin-10 (IL-10), has been determined at the resolution of 1.9 A and refined to an R-factor 0.191. The structure of this cytokine is similar to that of human IL-10 (hIL-10), forming an intercalated dimer of two 17 kDa polypeptides related by a crystallographic 2-fold symmetry axis. BCRF1 exhibits novel conformations of the N-terminal coil and of the loop between helices A and B compared to hIL-10. These regions are likely to be involved in binding of one or more components of the IL-10 receptor system, and thus the structural differences may account for the lower binding affinity and limited spectrum of biological activities of viral IL-10, compared to hIL-10.
authors.affiliation: Macromolecular Structure Laboratory, NCI-Frederick Cancer Research and Development Center, ABL-Basic Research Program, Frederick, MD 21702, USA.
authors.forename: A
authors.initials: A
authors.lastname: Zdanov
authors.forename: C
authors.initials: C
authors.lastname: Schalk-Hihi
authors.forename: S
authors.initials: S
authors.lastname: Menon
authors.forename: K W
authors.initials: KW
authors.lastname: Moore
authors.forename: A
authors.initials: A
authors.lastname: Wlodawer
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D016207:Cytokines / Q000737:chemistry / Q000648:ultrastructure; D004854:Herpesvirus 4, Human / Q000648:ultrastructure*; D006801:Humans; D016753:Interleukin-10 / Q000737:chemistry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D018123:Receptors, Interleukin / Q000648:ultrastructure; D053701:Receptors, Interleukin-10; D011991:Receptors, Virus / Q000648:ultrastructure; D011994:Recombinant Proteins; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014764:Viral Proteins / Q000737:chemistry / Q000648:ultrastructure*
chemical_list: C066460:BCRF1 protein, Human herpesvirus 4; D016207:Cytokines; D018123:Receptors, Interleukin; D053701:Receptors, Interleukin-10; D011991:Receptors, Virus; D011994:Recombinant Proteins; D014764:Viral Proteins; D016753:Interleukin-10