Human nucleotide excision repair protein XPA: summary of exafs studies on the Zn(II), Co(II) and Cd(II) associated minimal DNA-binding domain

摘要

The zinc in the metal-binding core of the DNA-binding domain of the nucleotide excision repair protein XPA (M98-F219) can be replaced with cadmium (II) and cobalt (II). Here, we summarize extended X-ray fine structure spectra collected on each protein in the lyophilized state and in 15% frozen aqueous glycerol solution. Under both conditions the Zn~(2+), Cd~(2+), and Co~(2+) are tetrahedrally coordinate to the sulfur atom of four cysteine residues with the Zn-S and Co-S bond lengths nearly identical, at 2.34 A, and the Cd-S bond length at 2.54 A.