The third LIM domain of Zyxin: Zyxin exhibits three copies of the LIM domain, an extensive proline-rich domain and a nuclear export signal. Localized at sites of cellsubstratum adhesion in fibroblasts, Zyxin interacts with alpha-actinin, members of the cysteine-rich protein (CRP) family, proteins that display Src homology 3 (SH3) domains and Ena/VASP family members. Zyxin and its partners have been implicated in the spatial control of actin filament assembly as well as in pathways important for cell differentiation. In addition to its functions at focal adhesion plaques, recent work has shown that zyxin moves from the sites of cell contacts to the nucleus, where it directly participates in the regulation of gene expression. As in other LIM domains, this domain family is 50-60 amino acids in size and shares two characteristic zinc finger motifs. The two zinc fingers contain eight conserved residues, mostly cysteines and histidines, which coordinately bond to two zinc atoms. LIM domains function as adaptors or scaffolds to support the assembly of multimeric protein.
Comment:The two zinc fingers contain eight conserved residues, mostly cysteines and histidines, which coordinately bond to two zinc atoms. The Zn binding residues of LIM domain are highly conserved.