Zinc-coordinating DNA-binding domains CXXC zinc finger factors CLASSLINK:http\://www.edgar-wingender.de/class 2.6.html Class Class description: CXXC zinc fingers contain two zinc ion binding 4-cysteine patterns, each of them comprising a CGxCxxC motif and a distantly located cysteine. One of these patterns (with lower-case Cs) is embedded within the other (with upper-case Cs): C-x(2)-C-x(2)-C-x(5,6)-c-x(2)-c-x(2)-c-x(9,15)-c-x(4)-C. The second and third cysteine of each motif lie within a short alpha-helix. The overall finger structure also forms a two-stranded antiparallel beta-sheet, the two beta-strands being located immediately N- and C-terminally adjacent to the CXXC zinc finger pattern. The CXXC zinc finger binds to DNA at CpG-containing sequences, most of the contacts are exerted by residues of an extended loop in the x(9,15) region of the above signature. (PMID 16990798)