1hnc
CRYSTAL STRUCTURE OF HUMAN CLASS MU GLUTATHIONE TRANSFERASE GSTM2-2: EFFECTS OF LATTICE PACKING ON CONFORMATIONAL HETEROGENEITY
|
OverviewOverview
The structures of three crystal forms of the class mu human glutathione, transferase GSTM2-2 have been determined. X-ray phase information was, obtained independently from molecular replacement and from anomalous, scattering by a single isomorphous derivative. One crystal form contains a, single monomer in the asymmetric unit and has been refined to 1.85 A with, an overall R factor of 22.6%. The second form contains a single dimer in, the asymmetric unit and has been refined to 3.5 A with an R factor of, 20.7%. The third form contains two dimers in the asymmetric unit and has, been refined to 3.0 A with an R factor of 25.0%. Although all three, crystal forms were grown from solutions that contained, glutathione-dinitrobenzene, electron density can only be seen for the, glutathione portion of the ligand. The first 202 residues in the seven, crystallographically independent monomers of GSTM2-2 are essentially, identical in structure. However, heterogeneity in the conformation of the, side-chain of Tyr115 is observed in the different monomers. The tertiary, structure of residues 1-202 is similar to that of the corresponding region, in the class mu isoform of glutathione transferase from rat, GST3-3 (Ji et, al. (1992), Biochemistry, 31, 10169-10184). However, significant, differences in the conformation of the two enzymes have been observed in, the region of the active site that binds hydrophobic substrates. These, differences include a 2 A shift in the carboxy terminus of a helix, and, significant heterogeneity in the conformation of the last 15 residues of, the carboxy terminus. The conformation and degree of disorder of the last, 15 residues correlates with the extent of protein-protein contacts within, the unit cell.
About this StructureAbout this Structure
1HNC is a Single protein structure of sequence from Homo sapiens with GDN as ligand. Active as Glutathione transferase, with EC number 2.5.1.18 Full crystallographic information is available from OCA.
ReferenceReference
Crystal structure of human class mu glutathione transferase GSTM2-2. Effects of lattice packing on conformational heterogeneity., Raghunathan S, Chandross RJ, Kretsinger RH, Allison TJ, Penington CJ, Rule GS, J Mol Biol. 1994 May 20;238(5):815-32. PMID:8182750
Page seeded by OCA on Mon Nov 12 17:20:32 2007