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Structural implications for the role of the N terminus in the ‘superactivation’ of collagenases
Author(s) -
Reinemer Peter,
Grams Frank,
Huber Robert,
Kleine Thomas,
Schnierer Susanne,
Piper Michael,
Tschesche Harald,
Bode Wolfram
Publication year - 1994
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(94)80370-6
Subject(s) - chemistry , collagenase , biophysics , microbiology and biotechnology , biochemistry , biology , enzyme
For the collagenases PMNL‐CL and FIB‐CL, the presence of the N‐terminal Phe 79 correlates with an increase in proteolytic activity. We have determined the X‐ray crystal structure of the recombinant Phe 79 ‐Gly 242 catalytic domain of human neutrophil collagenase (PMNL‐CL, MMP‐8) using the recently solved model of the Met 80 ‐Gly 242 form for phasing and subsequently refined it to a final crystalographic R ‐factor of 18.0% at 2.5 Å resolution. The PMNL‐CL catalytic domain is a spherical molecule with a flat active site cleft separating a smaller C‐terminal subdomain from a bigger N‐terminal domain, that harbours two zinc ions, namely a ‘structural’ and a ‘catalytic’ zinc, and two calcium ions. The N‐terminal segment prior to Pro 86 , which is disordered in the Met 80 ‐Gly 242 form, packs against a concave hydrophobic surface made by the C‐terminal helix. The N‐terminal Phe 79 ammonium group makes a salt link with the side chain carboxylate group of the strictly conserved Asp 232 . Stabilization of the catalytic site might be conferred via strong hydrogen bonds made by the adjacent, likewise strictly conserved Asp 233 with the characteristic ‘Met‐turn’, which forms the base of the active site residues.