Structural restraints NOE-derived distance restraints Intraresidue 439 Sequential 325 Medium (2 ≤ ∣i − j∣ ≤ 4) 337 Long (∣i − j∣> 4) 140 Total 1241 

 Cross-peak intensity categories Very strong (0–2.3 Å) 23 Strong (0–2.8 Å) 219 Medium (0–3.5 Å) 641 Weak (0–5.0 Å) 358 Total 1241 

 Statistics for accepted structures Number of accepted structures 45 CNS energy terms (kcal mol− 1) (mean ± SD)  E (total) 633.1 ± 11.3  E (van der Waals) 307.5 ± 3.9  E (distance restraints) 35.6 ± 3.9 No distance violations greater than 0.35 Å rmsd from the ideal geometry used within XPLOR  Bond lengths (Å) 0.0065  Bond angles (°) 0.68  Improper angles (°) 0.37 Ramachandran statistics (%) Residues 4–84 Residues 4–99 Most favored 93.5 94.0 Additionally allowed 6.1 5.6 Generously allowed 0.2 0.2 Disallowed 0.2 0.1 Atomic rmsd (Å) from the average structure (mean ± SD) Residues 4–84 Residues 4–99 N, Cα, C atoms 0.41 ± 0.13 0.47 ± 0.13 All heavy atoms 0.92 ± 0.15 0.97 ± 0.13