title: Molecular symmetry of the ClpP component of the ATP-dependent Clp protease, an Escherichia coli homolog of 20 S proteasome.
abstract: The ClpP component Clp protease from Escherichia coli has been crystallized and examined by X-ray crystallography and self-rotation function calculations. The crystal belongs to the monoclinic space group P2(1) with unit cell dimensions of a = 196.9 A, b = 104.3 A, c = 162.4 A and beta = 98.3 degrees. The X-ray diffraction pattern extends at least to 2.5 A Bragg spacing when exposed to CuK alpha X-rays. Self-rotation function analyses indicate that the ClpP oligomer has 72-point group symmetry. This symmetry suggests that the ClpP oligomer is a tetradecamer, (ClpP)14, consisting of two heptamers, (ClpP)7 stacked on top of each other in a head-to-head fashion. The measurement of crystal density indicates that two independent copies of the ClpP oligomers are present in the asymmetric unit, giving a crystal volume per protein mass (VM) of 2.73 A3/Da and a solvent content of 54.9% (v/v). Self-rotation function calculations are consistent with the presence of two ClpP tetradecamers in the asymmetric unit. The Patterson function suggests that a translation of x = 0.5 and y = 0.5 relates a pair of ClpP oligomers in one asymmetric unit to another pair in the other asymmetric unit. And the two independent tetradecamers in one asymmetric unit are related by a relative rotation of about 18 degrees around the 7-fold axis.
authors.affiliation: Department of Chemistry, Seoul National University, Korea.
authors.forename: D H
authors.initials: DH
authors.lastname: Shin
authors.forename: C S
authors.initials: CS
authors.lastname: Lee
authors.forename: C H
authors.initials: CH
authors.lastname: Chung
authors.forename: S W
authors.initials: SW
authors.lastname: Suh
mesh_terms: D000251:Adenosine Triphosphatases; D018360:Crystallography, X-Ray; D003546:Cysteine Endopeptidases / Q000737:chemistry*; D049071:Endopeptidase Clp; D004926:Escherichia coli / Q000201:enzymology*; D009097:Multienzyme Complexes / Q000737:chemistry*; D046988:Proteasome Endopeptidase Complex; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D012697:Serine Endopeptidases / Q000737:chemistry*
chemical_list: D009097:Multienzyme Complexes; D012697:Serine Endopeptidases; D049071:Endopeptidase Clp; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex; D000251:Adenosine Triphosphatases