The crystal structures of reduced pseudoazurin from Alcaligenes faecalis S‐6 at two pH values

FEBS Letters

Petratos, Kyriacos¹  Vakoufari, Eleni¹  Wilson, Keith S.² 

[1] Institute of Molecular Biology and Biotechnology (I.M.B.B.)-F.O.R.T.H., P.O. Box 1527, 711 10 Heraklion, Greece;European Molecular Biology Laboratory (EMBL) c/o DESY Notkestr. 85, 22603 Hamburg 52, Germany

关键词: Blue copper protein;    Crystal structure;    pH effect;    Pseudoazurin;    Redox state;    Alcaligenes faecalis;    CM;    carboxymethyl;    DEAE;    diethylaminoethyl;    IPTG;    isopropyl-β-d-thiogalactoside;    PMSF;    phenylmethylsulfonylfluoride;    rms;    root-mean-square;    SDS;    sodium dodecyl sulfate;    Tris;    tris(hydroxymethyl)amino-methane;   

DOI  :  10.1016/0014-5793(94)00544-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The structures of the reduced (Cu¹⁺) blue-copper protein pseudoazurin from Alcaligenes faecalis strain S-6 are refined at pH 7.8 and 4.4 using X-ray diffraction data to 1.8 Å resolution. The final R-factors for the high and low pH structures are 0.178 and 0.177, respectively. Comparing the reduced pseudoazurin at pH 7.8 with the oxidised (Cu²⁺) molecule, small changes are observed in the vicinity of the copper site and on the protein surface. At pH 4.4 the copper substituent imidazole of His⁸¹ rotates away from the metal with a concurrent movement of the latter towards the plane of the remaining three ligands (Sγ-Cys⁷⁸, Nδl-His⁴⁰ and Sδ-Met⁸⁶) thus the geometry of the copper site becomes planar trigonal.

【 授权许可】

Unknown