LCCL domain


In molecular biology, the LCCL domain is a protein domain which has been named after several well-characterised proteins that were found to contain it, namely Limulus clotting factor C, Cochlin and Lgl1. It is an about 100 amino acids domain whose C-terminal part contains a highly conserved histidine in a conserved motif YxxxSxxCxAAVHxGVI. The LCCL module is thought to be an autonomously folding domain that has been used for the construction of various modular proteins through exon-shuffling. It has been found in various metazoan proteins in association with complement B-type domains, C-type lectin domains, von Willebrand type A domains, CUB domains, discoidin lectin domains or CAP domains. It has been proposed that the LCCL domain could be involved in lipopolysaccharide binding. LCCL exhibits a novel fold.
Some proteins known to contain a LCCL domain include Limulus factor C, an LPS endotoxin-sensitive trypsin type serine protease which serves to protect the organism from bacterial infection; vertebrate cochlear protein cochlin or coch-5b2 ; and mammalian late gestation lung protein Lgl1, contains two tandem copies of the LCCL domain.