title: Crystal structure of recombinant human interleukin-4.
abstract: The crystal structure of recombinant human interleukin-4 (rhuIL-4) was initially determined at 3.5-A resolution by multiple isomorphous replacement techniques and subsequently refined to a resolution of 2.35 A by simulated annealing. The final crystallographic R-factor, based on all data in the range 6.0-2.35 A (7470 reflections), is 0.232. Bond lengths and bond angles in the molecule have root mean square deviations from ideal values of 0.016 A and 2.4 degrees, respectively. The overall structure is highly compact and globular with a predominantly hydrophobic core. The main structural feature of rhuIL-4 is a four alpha-helix bundle, which composes approximately 58% of the structure. The helices are arranged in a left-handed antiparallel bundle with two overhand connections. Within these connections is a two-stranded antiparallel beta-sheet. Both the tertiary and secondary structures of rhuIL-4 are similar to those of human granulocyte-macrophage colony-stimulating factor. Critical regions for receptor binding are proposed.
authors.affiliation: Department of Pathology, University of Alabama at Birmingham 35294.
authors.forename: M R
authors.initials: MR
authors.lastname: Walter
authors.forename: W J
authors.initials: WJ
authors.lastname: Cook
authors.forename: B G
authors.initials: BG
authors.lastname: Zhao
authors.forename: R P
authors.initials: RP
authors.lastname: Cameron
authors.forename: S E
authors.initials: SE
authors.lastname: Ealick
authors.forename: R L
authors.initials: RL
authors.lastname: Walter
authors.forename: P
authors.initials: P
authors.lastname: Reichert
authors.forename: T L
authors.initials: TL
authors.lastname: Nagabhushan
authors.forename: P P
authors.initials: PP
authors.lastname: Trotta
authors.forename: C E
authors.initials: CE
authors.lastname: Bugg
mesh_terms: D000595:Amino Acid Sequence; D003460:Crystallization; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000737:chemistry; D006801:Humans; D015847:Interleukin-4 / Q000737:chemistry*; D008969:Molecular Sequence Data; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D011994:Recombinant Proteins; D015847:Interleukin-4; D016178:Granulocyte-Macrophage Colony-Stimulating Factor