Interstitial collagenase

The catalytic domains of MMPs share very similar characteristics, having a general shape of oblate ellipsoid with a diameter of ~40 Å.

Following the sIII strand the sequence meets the 'S-shaped double loop' that is of primary importance for the peptide structure and catalytic activity (see further) as it extends to the cleft side "bulge", continuing to the only antiparallel β-strand sIV, which is prime importance for binding peptidic substrates or inhibitors by forming main chain hydrogen bond.

Following sIV, loop Gln186-Gly192 and β-strand sV are responsible for contributing with many ligands to the several metal ions present in the protein (read further).

A large open loop follows sV which has proven importance in substrate specificity within the MMPs family.

[11] A specific region (183)RWTNNFREY(191) has been identified as a critical segment of matrix metalloproteinase 1 for the expression of collagenolytic activity.