The fourth LIM domain of protein LIMPETin: LIMPETin contains 6 LIM domains at the C-terminal and an N-terminal PET domain. Four of the six LIM domains are highly homologous to the four and half LIM domain protein family and two of them show sequence similarity to the LIM domains of the Testin family. Thus, LIMPETin may be the recombinant product of genes coding testin and FHL proteins. In Schistosoma mansoni, where LIMPETin was first identified, LIMPETin is down regulated in sexually mature adult Schistosoma females compared to sexually immature adult females and adult male. Its differential expression indicates that it is a transcription regulator. 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.",