Meprin family, Alpha subunit, MATH domain; Meprins are multidomain extracellular metalloproteases capable of cleaving growth factors, cytokines, extracellular matrix proteins, and biologically active peptides. They are composed of two related subunits, alpha and beta, which form homo- or hetro-complexes where the basic unit is a disulfide-linked dimer. The alpha subunit is synthesized as a membrane spanning protein, however, it is cleaved during biosynthesis and loses its transmembrane domain. It oligomerizes into large complexes, containing 10-100 subunits (dimers that associate noncovalently), which are secreted as latent proteases and can move through extracellular spaces in a nondestructive manner. This allows delivery of the concentrated protease to sites containing activating enzymes, such as sites of inflammation, infection or cancerous growth. Meprin alpha shows preference for small or hydrophobic residues at the P1 and P1' sites of its substrate. Both alpha and beta subunits contain a catalytic astacin (M12 family) protease domain followed by the adhesion or interaction domains MAM, MATH and AM. The MATH and MAM domains provide symmetrical intersubunit disulfide bonds necessary for the dimerization of meprin subunits. The MATH domain may also be required for folding of an activable zymogen.
Feature 1:putative substrate binding site [chemical binding site]
Evidence:
Comment:Based on the substrate binding site of TRAFs and HAUSP. The binding site residues involved in the binding of TRAFs to TNFRs and of HAUSP to p53/MDM2 partially overlap, but are not conserved. The substrate binding pocket located in the MATH domain for members of this superfamily may be in the same location, but the specific interactions are different.