Yet undefined DNA-binding domains NFX1-type putative zinc finger factors Class Class description: A large class of proteins, with most known members from the plant kingdom. The DNA-binding domain comprises a cysteine-rich region with a repeated motif of the signature C-x(1-6)-H-x-C-x3-C-h-x(3-4)-C-x(1-10)-C (with the lower-case histidine occasionally replaced by another cysteine). Although this motif has been denominated 'NFX1-type zinc finger', neither zinc ion binding nor its 3D structure have been unravelled so far. (PMID 7964459, PMID 20522174)