Crystallization and preliminary X‐ray investigation of the Escherichia coli molecular chaperone cpn60 (GroEL)

FEBS Letters

Carlemalm, Eric³  Surin, Brian P.⁴  Svensson, L.Anders¹  Spangfort, Michael D.²  Oppentocht, Jantina E.²  Dixon, Nicholas E.⁴  Weibull, Claes⁵ 

[1] Department of Molecular Biophysics, Chemical Center, University of Lund, S-221 00 Lund, Sweden;Department of Biochemistry, Chemical Center, University of Lund, S-221 00 Lund, Sweden;Electron Microscopy Unit, Medical Faculty, University of Lund, S-221 85 Lund, Sweden;Center for Molecular Structure and Function, Research School of Chemistry, Australian National University, Canberra ACT 2601, Australia;Department of Microbiology, University of Lund, S-221 00 Lund, Sweden

关键词: Molecular chaperone;    GroEL;    Escherichia coli;    Crystallization;    X-ray analysis;    cpn60;    chaperonin 60 or GroEL;    cpn1O;    chaperonin 10 or GroES;    PEG;    polyethylene glycol;    OGP;    n-octyl-β-d-glucopyra-noside;    MES;    4-morpholinoethanesulphonic acid;    Tris;    tris[hydroxy-methyl]aminomethane;    SDS;    sodium dodecyl sulphate;    LB medium;    Luria-Bertani medium;   

DOI  :  10.1016/0014-5793(93)80083-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The Escherichia coli molecular chaperone, cpn60 (GroEL), has been purified from an overproducing E. coli strain and crystallized. Of the two crystal forms that were obtained, one was found to be suitable for crystallographic and structural studies at low resolution. Preliminary X-ray investigation of the crystals show unit cell dimensions: a = 143.3, b = 154.6 and c = 265 Å, with α = 82°, β = 95° and γ = 107°. The space group is P1 and the crystals diffract to a maximum of 7 Å when using CuK_α X-rays from a rotating anode. Both electron microscopy and non-denaturing electrophoretic analysis of redissolved cpn60 crystals show that cpn60 crystallizes in the native oligomeric form. Comparison between the dimensions of oligomeric cpn60 and the crystallographic unit cell volume suggests that the unit cell contains two oligomeric cpn60 molecules. The V _M value for two cpn60 molecules per unit cell is 3.5 ų/Da, corresponding to a water content of 65%. Electrophoretic analysis under denaturing conditions shows that the cpn60 in crystals is heterogeneous, and this probably explains the limited resolution of the diffraction data.

【 授权许可】

Unknown