TY - JOUR
T1 - Crystal structure of the cyanide-inhibited Xenopus laevis Cu,Zn superoxide dismutase at 98 K
AU - Carugo, Kristina Djinovic
AU - Battistoni, Andrea
AU - Carrì, Maria Teresa
AU - Polticelli, Fabio
AU - Desideri, Alessandro
AU - Rotilio, Giuseppe
AU - Coda, Alessandro
AU - Bolognesi, Martino
PY - 1994/7/25
Y1 - 1994/7/25
N2 - The crystal structure of cyanide-inhibited X. laevis Cu,Zn superoxide dismutase has been studied and refined based on diffraction data collected at 98 K. The final R-factor for the 27,299 reflections in the 10.0-1.7 Å resolution range is 0.170. The cyanide anion, which is a competitive inhibitor expected to mimic the superoxide binding mode, binds directly to the active site copper atom, replacing the coordinated water molecule. Moreover, the anion establishes a strong electrostatic interaction with the guanidinium group of the conserved active site residue Arg141. The coordination sphere of Cu2+ is partly altered with respect to the uninhibited enzyme: a displacement of 0.41 Å in subunit A, and 0.27 Å in subunit B of the dimeric enzyme is observed for the Cu2+ ions. Only two ligands in the Cu2+ coordination sphere (His46 and His118) are significantly affected by cyanide binding, whereas virtually no rearrangement of the Zn2+ ligands is reported.
AB - The crystal structure of cyanide-inhibited X. laevis Cu,Zn superoxide dismutase has been studied and refined based on diffraction data collected at 98 K. The final R-factor for the 27,299 reflections in the 10.0-1.7 Å resolution range is 0.170. The cyanide anion, which is a competitive inhibitor expected to mimic the superoxide binding mode, binds directly to the active site copper atom, replacing the coordinated water molecule. Moreover, the anion establishes a strong electrostatic interaction with the guanidinium group of the conserved active site residue Arg141. The coordination sphere of Cu2+ is partly altered with respect to the uninhibited enzyme: a displacement of 0.41 Å in subunit A, and 0.27 Å in subunit B of the dimeric enzyme is observed for the Cu2+ ions. Only two ligands in the Cu2+ coordination sphere (His46 and His118) are significantly affected by cyanide binding, whereas virtually no rearrangement of the Zn2+ ligands is reported.
KW - Crystal structure
KW - Cyanide inhibition
KW - Superoxide dismutase
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U2 - 10.1016/0014-5793(94)00651-2
DO - 10.1016/0014-5793(94)00651-2
M3 - Article
C2 - 8045309
AN - SCOPUS:0028301573
VL - 349
SP - 93
EP - 98
JO - FEBS Letters
JF - FEBS Letters
SN - 0014-5793
IS - 1
ER -