The fourth LIM domain of Paxillin: Paxillin is an adaptor protein, which recruits key components of the signal-transduction machinery to specific sub-cellular locations to respond to environmental changes rapidly. The C-terminal region of paxillin contains four LIM domains which target paxillin to focal adhesions, presumably through a direct association with the cytoplasmic tail of beta-integrin. The N-terminal of paxillin is leucine-rich LD-motifs. Paxillin is found at the interface between the plasma membrane and the actin cytoskeleton. The binding partners of paxillin are diverse and include protein tyrosine kinases, such as Src and FAK, structural proteins, such as vinculin and actopaxin, and regulators of actin organization. Paxillin recruits these proteins to their function sites to control the dynamic changes in cell adhesion, cytoskeletal reorganization and gene expression. 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.",