ZINC AS A STRUCTURAL AND FOLDING ELEMENT OF PROTEINS WHICH INTERACT WITH DNA

Zinc proteins involved in the control of gene expression include two t ypes which contain zinc binuclear clusters; fungal transcription facto rs containing DNA binding domains organized around a Zn(2)Cys(6) clust er and the V(D)J recombination-activating proteins, RAG1's, of higher eukaryotes in which the dimerization domains contain a Zn(2)Cys(5)His( 2) cluster. Two solution structures of Zn(2)Cys(6) cluster domains are compared along with the crystal structure of the dimerization domain of RAG1. The dimerization domain of RAG1 contains four zinc ions and i s organized around a zinc finger, a zinc RING finger and a zinc binucl ear cluster. Protein folds stabilized by multiple zinc sites are discu ssed. (C) 1998 Elsevier Science S.A. All rights reserved.