The second LIM domain of Lhx7 and Lhx8: Lhx7 and Lhx8 belong to the LHX protein family, which features two tandem N-terminal LIM domains and a C-terminal DNA binding homeodomain. Members of LHX family are found in the nucleus and act as transcription factors or cofactors. LHX proteins are critical for the development of specialized cells in multiple tissue types, including the nervous system, skeletal muscle, the heart, the kidneys, and endocrine organs such as the pituitary gland and the pancreas. Studies using mutant mice have revealed roles for Lhx7 and Lhx8 in the development of cholinergic neurons in the telencephalon and in basal forebrain development. Mice lacking alleles of the LIM-homeobox gene Lhx7 or Lhx8 display dramatically reduced number of forebrain cholinergic neurons. In addition, Lhx7 mutation affects male and female mice differently, with females appearing more affected than males. 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.