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Zinc to cadmium replacement in the A. thaliana SUPERMAN Cys 2 His 2 zinc finger induces structural rearrangements of typical DNA base determinant positions
Author(s) -
Malgieri Gaetano,
Zaccaro Laura,
Leone Marilisa,
Bucci Enrico,
Esposito Sabrina,
Baglivo Ilaria,
Del Gatto Annarita,
Russo Luigi,
Scandurra Roberto,
Pedone Paolo V.,
Fattorusso Roberto,
Isernia Carla
Publication year - 2011
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.21680
Subject(s) - chemistry , zinc , cadmium , zinc finger , zinc toxicity , stereochemistry , crystallography , biophysics , biochemistry , transcription factor , organic chemistry , gene , biology
Among heavy metals, whose toxicity cause a steadily increasing of environmental pollution, cadmium is of special concern due to its relatively high mobility in soils and potential toxicity at low concentrations. Given their ubiquitous role, zinc fingers domains have been proposed as mediators for the toxic and carcinogenic effects exerted by xenobiotic metals. To verify the structural effects of zinc replacement by cadmium in zinc fingers, we have determined the high resolution structure of the single Cys 2 His 2 zinc finger of the Arabidopsis thaliana SUPERMAN protein (SUP37) complexed to the cadmium ion by means of UV–vis and NMR techniques. SUP37 is able to bind Cd(II), though with a dissociation constant higher than that measured for Zn(II). Cd‐SUP37 retains the ββα fold but experiences a global structural rearrangement affecting both the relative orientation of the secondary structure elements and the position of side chains involved in DNA recognition: among them Ser17 side chain, which we show to be essential for DNA binding, experiences the largest displacement. © 2011 Wiley Periodicals, Inc. Biopolymers 95: 801‐810, 2011.