title: The structure of augmenter of liver regeneration crystallized in the presence of 50 mM CdCl2 reveals a novel Cd2Cl4O6 cluster that aids in crystal packing.
abstract: The crystal structure of the protein augmenter of liver regeneration containing a 14-residue hexahistidine purification tag (hsALR) has been determined to 2.4 Å resolution by Cd-SAD using a highly redundant data set collected on a rotating-anode home X-ray source and processed in 1998. The hsALR crystal structure is a tetramer composed of two homodimers bridged by a novel Cd(2)Cl(4)O(6) cluster via binding to the side-chain carboxylate groups of two solvent-exposed aspartic acid residues. A comparison with the native sALR tetramer shows that the cluster dramatically changes the hsALR dimer-dimer interface, which can now better accommodate the extra 14 N-terminal residues associated with the purification tag. The refined 2.4 Å resolution structure is in good agreement with both the X-ray data (R(cryst) of 0.165, R(free) of 0.211) and the expected stereochemistry (r.m.s. deviations from ideality for bond lengths and bond angles of 0.007 Å and 1.15°, respectively).
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA.
authors.forename: Quentin
authors.initials: Q
authors.lastname: Florence
authors.forename: Chia-Kuei
authors.initials: CK
authors.lastname: Wu
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Habel
authors.forename: J Tucker
authors.initials: JT
authors.lastname: Swindell
authors.forename: Bi-Cheng
authors.initials: BC
authors.lastname: Wang
authors.forename: John P
authors.initials: JP
authors.lastname: Rose
mesh_terms: D000143:Acids / Q000737:chemistry*; D019256:Cadmium Chloride / Q000737:chemistry*; D019187:Cadmium Compounds / Q000737:chemistry*; D018360:Crystallography, X-Ray; D003579:Cytochrome Reductases / Q000737:chemistry*; D019281:Dimerization; D006801:Humans; D008958:Models, Molecular; D050862:Oxidoreductases Acting on Sulfur Group Donors; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000737:chemistry*
chemical_list: D000143:Acids; D019187:Cadmium Compounds; D011506:Proteins; D003579:Cytochrome Reductases; C500897:GFER protein, human; D050862:Oxidoreductases Acting on Sulfur Group Donors; D019256:Cadmium Chloride