The second LIM domain of Testin: Testin contains three C-terminal LIM domains and a PET protein-protein interaction domain at the N-terminal. Testin is a cytoskeleton associated focal adhesion protein that localizes along actin stress fibers, at cell-cell-contact areas, and at focal adhesion plaques. Testin interacts with a variety of cytoskeletal proteins, including zyxin, mena, VASP, talin, and actin and it is involved in cell motility and adhesion events. Knockout mice experiments reveal that tumor repressor function of testin. LIM domains are 50-60 amino acids in size and share 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 complexes.
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.
Jiyao W et al.(2023). "The conserved domain database in 2023.",