MAM is an acronym derived from meprin, A-5 protein, and receptor protein-tyrosine phosphatase mu. The MAM domain consists of approximately 170 amino acids. It occurs in several cell surface proteins and is likely to have an adhesive function [ PUBMED:8387703 ]. The domain has been shown to play a role in homodimerization … expand

MAM is an acronym derived from meprin, A-5 protein, and receptor protein-tyrosine phosphatase mu. The MAM domain consists of approximately 170 amino acids. It occurs in several cell surface proteins and is likely to have an adhesive function [ PUBMED:8387703 ]. The domain has been shown to play a role in homodimerization of protein-tyrosine phosphatase mu [ PUBMED:7782276 ] and appears to help determine the specificity of these interactions. It contains four conserved cysteines which probably form two disulfide bridges. It has been reported that certain cysteine mutations in the MAM domain of murine meprin A result in the formation of monomeric meprin, which has altered stability and activity [ PUBMED:8798668 ]. This indicates that these domain-domain interactions are critical for structure and function of the enzyme.

Proteins containing this domain are listed below.

• Meprin. This cell surface glycoprotein contains a zinc-metalloprotease domain capable of degrading a variety of polypeptides. Meprin is composed of two structurally related subunits (alpha and beta) that form homo- or heterotetramers by the non-covalent association of two disulfide-linked dimers. In both subunits, the MAM domain is located after the catalytic domain. It has also been shown that the MAM domain of meprins is necessary for correct folding and transport through the secretory pathway [ PUBMED:9857066 ].
• Neuropilin (A5 antigen), a calcium-independent cell adhesion molecule that function during the formation of certain neuronal circuits. The sequence contains 2 CUB domains and a MAM domain.
• Receptor-like tyrosine protein phosphatases Mu, Kappa and PCP-2 ( EC:3.1.3.48 ). These PTPases have an extracellular region which consists of a MAM domain followed by an Ig-like domain and four fibronectin-type III domains.
• Vertebrate enteropeptidase ( EC:3.4.21.9 ), a type II membrane protein of the intestinal brush border, which activates trypsinogen. It consists at least of a catalytic light chain and a multidomain heavy chain which has 2 LDL receptor class A domains, a MAM domain, a SRCR domain and a CUB domain.
• Apical endosomal glycoprotein from rat, a protein probably involved in the sorting and selective transport of receptors and ligands across polarized epithelia. This protein contains 6 MAM domains.
• Xenopus laevis thyroid hormone induced protein B. This protein contains 4 MAM domains.
• Pig zonadhesin, a protein that binds in a species-specific manner to the zona pellucida of the egg.