Solution structure of recombinant human interleukin-6.
Xu, G.Y., Yu, H.A., Hong, J., Stahl, M., McDonagh, T., Kay, L.E., Cumming, D.A.(1997) J Mol Biol 268: 468-481
- PubMed: 9159484 
- DOI: https://doi.org/10.1006/jmbi.1997.0933
- Primary Citation of Related Structures:  
1IL6, 2IL6 - PubMed Abstract: 
Interleukin-6 (IL-6) is a 185 amino acid cytokine which exerts multiple biological effects in vivo and whose dysregulation underlies several disease processes. The solution structure of recombinant human interleukin-6 has now been determined using heteronuclear three and four-dimensional NMR spectroscopy. The structure of the molecule was determined using 3044 distance and torsion restraints derived by NMR spectroscopy to generate an ensemble of 32 structures using a combined distance geometry/simulated annealing protocol. The protein contains five alpha-helices interspersed with variable-length loops; four of these helices constitute a classical four-helix bundle with the fifth helix located in the CD loop. There were no distance violations greater than 0.3 A in any of the final 32 structures and the ensemble has an average-to-the-mean backbone root-mean-square deviation of 0.50 A for the core four-helix bundle. Although the amino-terminal 19 amino acids are disordered in solution, the remainder of the molecule has a well defined structure that shares many features displayed by other long-chain four-helix bundle cytokines. The high-resolution NMR structure of hIL-6 is used to rationalize available mutagenesis data in terms of a heteromeric receptor complex.
Organizational Affiliation: 
Small Molecule Drug Discovery, Genetics Institute, Cambridge, MA 02140, USA.