The second LIM domain of Lhx1 (also known as Lim1) and Lhx5
The second LIM domain of Lhx1 (also known as Lim1) and Lhx5. Lhx1 and Lhx5 are closely related members of 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. Lhx1 is required for regulating the vertebrate head organizer, the nervous system, and female reproductive tract development. During embryogenesis in the mouse, Lhx1 is expressed early in mesodermal tissue, then later during urogenital, kidney, liver, and nervous system development. In the adult, expression is restricted to the kidney and brain. A mouse embryos with Lhx1 gene knockout cannot grow normal anterior head structures, kidneys, and gonads, but with normally developed trunk and tail morphology. In the developing nervous system, Lhx1 is required to direct the trajectories of motor axons in the limb. Lhx1 null female mice lack the oviducts and uterus. Lhx5 protein may play complementary or overlapping roles with Lhx1. The expression of Lhx5 in the anterior portion of the mouse neural tube suggests a role in patterning of the forebrain. All 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.",