Crystal structure of interleukin-19 defines a new subfamily of helical cytokines.
Interleukin-19 (IL-19) is a novel cytokine that was initially identified during a sequence data base search aimed at finding potential IL-10 homologs. IL-19 shares a receptor complex with IL-20, indicating that the biological activities of these two cytokines overlap and that both may play an important role in regulating development and proper functioning of the skin. We determined the crystal structure of human recombinant IL-19 and refined it at 1.95-A resolution to an R-factor of 0.157. Unlike IL-10, which forms an intercalated dimer, the molecule of IL-19 is a monomer made of seven amphipathic helices, A-G, creating a unique helical bundle. On the basis of the observed structure, we propose that IL-19, IL-20, and other putative members of the proposed IL-10 family together form a distinct subfamily of helical cytokines.
Chang
Changsoo
C
Protein Structure Section, Macromolecular Crystallography Laboratory, Center for Cancer Research, National Cancer Institute-Frederick, National Institutes of Health, Maryland 21702-1201, USA.
Magracheva
Eugenia
E
Kozlov
Serguei
S
Fong
Steven
S
Tobin
Gregory
G
Kotenko
Sergei
S
Wlodawer
Alexander
A
Zdanov
Alexander
A
D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D017124:Conserved Sequence; D018360:Crystallography, X-Ray; D004331:Drosophila melanogaster; D006801:Humans; D016753:Interleukin-10 / Q000737:chemistry*; D007378:Interleukins / Q000737:chemistry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry; D012680:Sensitivity and Specificity; D016415:Sequence Alignment; D014162:Transfection
C421250:IL19 protein, human; D007378:Interleukins; D011994:Recombinant Proteins; D016753:Interleukin-10; C422042:interleukin 20