SP, Signal peptide; Pro, pro-domain; Cat, catalytic domain; L1, linker 1; Hpx, hemopexin domain; FN, fibronectin type II repeats; VN, vitronectin-type domain; TM, transmembrane domain; Cys, cysteine-rich domain; Ig, immunoglobulin-like domain; L2, linker 2; CT, cytoplasmic tail; GPI, GPI-anchor signal sequence. RX(K/R)R: PC recognition sequence; MT-Loop: eight-amino acid insertion characteristic to TM-type MT-MMPs. Hpx domain contains one di-sulfide bond (C-C). MT1-MMP is palmitoylated at Cys574 in the CT.