LIM domain
LIM domains are protein structural domains, composed of two contiguous zinc finger domains, separated by a two-amino acid residue hydrophobic linker. They are named after their initial discovery in the proteins Lin11, Isl-1 & Mec-3. LIM-domain containing proteins have been shown to play roles in cytoskeletal organisation, organ development and oncogenesis. LIM-domains mediate protein:protein interactions that are critical to cellular processes.
LIM domains have highly divergent sequences, apart from certain key residues. The sequence divergence allow a great many different binding sites to be grafted onto the same basic domain. The conserved residues are those involved in zinc binding or the hydrophobic core of the protein. The sequence signature of LIM domains is as follows:
[C]-[X]2-4-[C]-[X]13-19-[W]-[H]-[X]2-4-[C]-[F]-[LVI]-[C]-[X]2-4-[C]-[X]13-20-C-[X]2-4-[C]
LIM domains frequently occur in multiples, as seen in proteins such as TES, LMO4, and can also be attached to other domains in order to confer a binding or targeting function upon them, such as LIM-kinase.
