Homologous Superfamily

Cytokine IL1/FGF (IPR008996)

Short name: IL1/FGF

Overlapping entries


This entry includes IL-1 and FGF.

The interleukin-1 (IL-1) and fibroblast growth factor (FGF, also known as heparin-binding growth factor) families share low sequence similarity (about 25% [PMID: 1849658]) but have very similar structures. They belong to a superfamily that also contains the Kunitz-type soybean trypsin inhibitors (STIs), all of which have very similar structures. However, IL-1 and FGF share no sequence similarity with the STI family.

The crystal structures of interleukin-1 beta and HGF1 have been solved, showing both families to have the same 12-stranded beta-sheet structure [PMID: 1738162]; the beta-sheets are arranged in 3 similar lobes around a central axis, 6 strands forming an anti-parallel beta-barrel [PMID: 1707542, PMID: 4071057]. The beta-sheets are generally well preserved and the crystal structures superimpose in these areas. The intervening loops are less well conserved - the loop between beta-strands 6 and 7 is slightly longer in interleukin-1 beta.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.