pfam07703: A2M_BRD (This model is not part of the current CDD release)
Alpha-2-macroglobulin bait region domain
Alpha-2-macroglobulins (A2Ms) are plasma proteins that trap and inhibit a broad range of proteases and are major components of the eukaryotic innate immune system. However, A2M-like proteins were identified in pathogenically invasive bacteria and species that colonize higher eukaryotes. This domain is found in eukaryotic and bacterial proteins. In human A2Ms, this domain encompasses macroglobulin-like domain MG5 and 6 including bait region. In Salmonella enterica ser A2Ms, this domain encompasses MG7 and MG8 including the bait region. The Bait region is cleaved by proteases, followed by a large conformational change that blocks the target protease within a cage-like complex. This model of protease entrapment is recognised as the Venus flytrap mechanism.
Jiyao W et al.(2023). "The conserved domain database in 2023.",