title: Three-dimensional structure of Schistosoma japonicum glutathione S-transferase fused with a six-amino acid conserved neutralizing epitope of gp41 from HIV.
abstract: The 3-dimensional crystal structure of glutathione S-transferase (GST) of Schistosoma japonicum (Sj) fused with a conserved neutralizing epitope on gp41 (glycoprotein, 41 kDa) of human immunodeficiency virus type 1 (HIV-1) (Muster T et al., 1993, J Virol 67:6642-6647) was determined at 2.5 A resolution. The structure of the 3-3 isozyme rat GST of the mu gene class (Ji X, Zhang P, Armstrong RN, Gilliland GL, 1992, Biochemistry 31:10169-10184) was used as a molecular replacement model. The structure consists of a 4-stranded beta-sheet and 3 alpha-helices in domain 1 and 5 alpha-helices in domain 2. The space group of the Sj GST crystal is P4(3)2(1)2, with unit cell dimensions of a = b = 94.7 A, and c = 58.1 A. The crystal has 1 GST monomer per asymmetric unit, and 2 monomers that form an active dimer are related by crystallographic 2-fold symmetry. In the binding site, the ordered structure of reduced glutathione is observed. The gp41 peptide (Glu-Leu-Asp-Lys-Trp-Ala) fused to the C-terminus of Sj GST forms a loop stabilized by symmetry-related GSTs. The Sj GST structure is compared with previously determined GST structures of mammalian gene classes mu, alpha, and pi. Conserved amino acid residues among the 4 GSTs that are important for hydrophobic and hydrophilic interactions for dimer association and glutathione binding are discussed.
authors.affiliation: Biophysics Branch, George C. Marshall Space Flight Center, National Aeronautics and Space Administration, Huntsville, Alabama 35812, USA.
authors.forename: K
authors.initials: K
authors.lastname: Lim
authors.forename: J X
authors.initials: JX
authors.lastname: Ho
authors.forename: K
authors.initials: K
authors.lastname: Keeling
authors.forename: G L
authors.initials: GL
authors.lastname: Gilliland
authors.forename: X
authors.initials: X
authors.lastname: Ji
authors.forename: F
authors.initials: F
authors.lastname: Rüker
authors.forename: D C
authors.initials: DC
authors.lastname: Carter
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D001665:Binding Sites; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D018360:Crystallography, X-Ray; D000939:Epitopes / Q000737:chemistry* / Q000235:genetics / Q000276:immunology; D005978:Glutathione; D005982:Glutathione Transferase / Q000378:metabolism; D015700:HIV Envelope Protein gp41 / Q000737:chemistry* / Q000235:genetics / Q000276:immunology; D015497:HIV-1 / Q000235:genetics / Q000276:immunology*; D015801:Helminth Proteins / Q000737:chemistry* / Q000235:genetics / Q000276:immunology; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000737:chemistry* / Q000276:immunology; D012549:Schistosoma japonicum / Q000201:enzymology* / Q000235:genetics / Q000276:immunology; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D000911:Antibodies, Monoclonal; D000939:Epitopes; D015700:HIV Envelope Protein gp41; D015801:Helminth Proteins; D011993:Recombinant Fusion Proteins; D005982:Glutathione Transferase; D005978:Glutathione