The second LIM domain of Four and a half LIM domains protein 5 (FHL5)
The second LIM domain of Four and a half LIM domains protein 5 (FHL5): FHL5 is a tissue-specific coactivator of CREB/CREM family transcription factors , which are highly expressed in male germ cells and is required for post-meiotic gene expression. FHL5 associates with CREM and confers a powerful transcriptional activation function. Activation by CREB has known to occur upon phosphorylation at an essential regulatory site and the subsequent interaction with the ubiquitous coactivator CREB-binding protein (CBP). However, the activation by FHL5 is independent of phosphorylation and CBP association. It represents a new route for transcriptional activation by CREM and CREB. 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.