Comparison of the solution nuclear magnetic resonance and X-ray crystal structures of human recombinant interleukin-1...

The solution structure of interleukin-1 beta determined by nuclear magnetic resonance spectroscopy is compared to three independently solved X-ray structures at 2 A resolution. It is shown that the solution and X-ray structures are very similar, both locally and globally. The atomic root-mean-square (r.m.s.) difference between the solution and X-ray structures is approximately 0.9 A for backbone atoms, approximately 1.5 A for all atoms and approximately 1 A for all atoms of internal residues. The largest differences are confined to some of the loops and turns connecting beta-strands. The atomic r.m.s. distribution of the 32 calculated solution structures about their mean co-ordinate positions (approximately 0.4 A for backbone atoms, approximately 0.8 A for all atoms and approximately 0.5 A for all atoms of internal residues) is approximately the same as the atomic r.m.s. differences between the three X-ray structures, indicating that the positional errors in the atomic co-ordinates determined by the two methods are similar.