Sequence homology predicts that the human MMP-27 gene encodes the canonical domains shared by most MMPs ( annotation based on Uniprot entry Q9H306 ) : ( i ) a signal peptide ( residues 1-17 ), ( ii ) a propeptide ( 18-98 ) containing the cysteine switch motif ( 89-96 ), ( iii ) a catalytic domain ( 99-263 ) containing the typical HEXXHXXGXXH motif of the metzincins ( M10 and M12 families of the MEROPS [ 2 ] database ), ( iv ) a proline-rich hinge region ( 264-278 ) and ( v ) a hemopexin-like domain ( 279-465 ) folded as a four-bladed ?-propeller through disulfide bond formation between the two flanking Cys residues ( Cys279 and Cys465 ).
