title: The solution structure of a class II major histocompatibility complex superantigen binding domain.
abstract: We have used 600 MHz 1H NMR spectroscopy data to determine the solution structure of a 31-residue domain of a murine class II major histocompatibility (MHC) protein. This domain, I-Ab(beta)-(60-90), binds to the superantigen staphylococcal enterotoxin A. Distance geometry and dynamical simulated annealing calculations were performed using NOESY- and COSY-deduced constraints. I-Ab(beta)-(60-90), which is mostly alpha-helical, is more similar to the corresponding region of the class II MHC protein HLA-DR1 than to the class I MHC protein HLA-A2. Arg-72 and Arg-80 lie on the same side of the helix and face away from the antigenic peptide binding groove. His-81, implicated in both superantigen and peptide binding, is located midway between the surface defined by Arg-72/Arg-80 and residues that define the inside of the peptide binding groove, allowing for its participation in both types of binding.
authors.affiliation: Comprehensive Cancer Care Center, Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, 35294, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Jablonsky
authors.forename: P S
authors.initials: PS
authors.lastname: Subramaniam
authors.forename: H M
authors.initials: HM
authors.lastname: Johnson
authors.forename: J K
authors.initials: JK
authors.lastname: Russell
authors.forename: N R
authors.initials: NR
authors.lastname: Krishna
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000949:Histocompatibility Antigens Class II / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015394:Molecular Structure
chemical_list: D000949:Histocompatibility Antigens Class II