Abstract
Glycosylation-inhibiting factor (GIF) is a cytokine that is involved in the regulation of IgE synthesis. The crystal structure of recombinant human GIF was determined by the multiple isomorphous replacement method. The structure was refined to an R factor of 0.168 at 1.9 Å resolution. The overall structure is seen to consist of three interconnected subunits forming a barrel with three 6-stranded β-sheets on the inside and six α-helices on the outside. There is o 5-Å-diameter 'hole' through the middle of the barrel. The barrel structure of GIF in part resembles other 'trefoil' cytokines such as interleukin 1 and fibroblast growth factor. Each subunit has a new class of α + β sandwich structure consisting of two β-α-β motifs. These β-α-β motifs are related by a pseudo-twofold axis and resemble both interleukin 8 and the peptide binding domain of major histocompatibility complex protein, although the topology of the polypeptide chain is quite different.
Original language | English (US) |
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Pages (from-to) | 3007-3010 |
Number of pages | 4 |
Journal | Proceedings of the National Academy of Sciences of the United States of America |
Volume | 93 |
Issue number | 7 |
DOIs | |
State | Published - Apr 2 1996 |
Externally published | Yes |
Keywords
- cytokine
- multiple isomorphous replacement
- x-ray crystallography
- α + β sandwich structure
ASJC Scopus subject areas
- General