STRUCTURAL FEATURES OF A SUPERFAMILY OF ZINC-ENDOPEPTIDASES - THE METZINCINS

A large number of zinc endopeptidases contain an HEXXHXXGXXH consensus motif in their catalytic site (single letter code; X is any amino aci d residue). These enzymes can be grouped into four distinct families, the astacins, the adamalysins, the serralysins and the matrix metallop roteinases (matrixins). Despite a low degree of sequence similarity, t heir catalytic modules are topologically similar. A topology derived s equence alignment suggests that the four families form a superfamily, called the metzincins because of a perfectly superimposable methionine residue close to the zinc-binding active site. Topological similarity to the thermolysin-like enzymes indicates that these enzymes may have had a common ancestor.