title: New crystal forms and low resolution structure analysis of 20S proteasomes from bovine liver.
abstract: 20S proteasomes from higher eukaryotes have immunological functions rather than those from archibacteria or yeast. To clarify the mechanism of the sorting and production of antigen-presenting peptides, it is important and worthwhile to determine the structure of mammalian proteasomes using a third generation synchrotron radiation source. Here we report new crystal forms of 20S proteasomes from bovine liver and preliminary structure analysis of them. The crystals belong to the same space group but have different cell dimensions. One crystal (form I) belongs to space group P2(1)2(1)2(1) with unit cell dimensions of a = 124.8, b =197.4, c =323.8 A, and diffracts to 3.0 A resolution. The other crystal (form II) belongs to the same space group with a =115.1, b =205.6, c =316. 0 A, and diffracts to 4.0 A resolution. The diffraction data for the form I crystal provided an interpretable electron density map for presenting the structural differences from yeast proteasomes.
authors.affiliation: Faculty of Science, Himeji Institute of Technology, Kohto, Kamigori, Hyogo 678-1297, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Tomisugi
authors.forename: M
authors.initials: M
authors.lastname: Unno
authors.forename: T
authors.initials: T
authors.lastname: Mizushima
authors.forename: Y
authors.initials: Y
authors.lastname: Morimoto
authors.forename: N
authors.initials: N
authors.lastname: Tanahashi
authors.forename: K
authors.initials: K
authors.lastname: Tanaka
authors.forename: T
authors.initials: T
authors.lastname: Tsukihara
authors.forename: N
authors.initials: N
authors.lastname: Yasuoka
mesh_terms: D000818:Animals; D002417:Cattle; D018360:Crystallography, X-Ray; D003546:Cysteine Endopeptidases / Q000737:chemistry*; D008099:Liver / Q000201:enzymology; D008958:Models, Molecular; D009097:Multienzyme Complexes / Q000737:chemistry*; D046988:Proteasome Endopeptidase Complex; D017434:Protein Structure, Tertiary; D017356:Synchrotrons
chemical_list: D009097:Multienzyme Complexes; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex