1.56 A structure of mature truncated human fibroblast collagenase.
The X-ray crystal structure of a 19 kDa active fragment of human fibroblast collagenase has been determined by the multiple isomorphous replacement method and refined at 1.56 A resolution to an R-factor of 17.4%. The current structure includes a bound hydroxamate inhibitor, 88 waters and three metal atoms (two zincs and a calcium). The overall topology of the enzyme, comprised of a five stranded beta-sheet and three alpha-helices, is similar to the thermolysin-like metalloproteinases. There are some important differences between the collagenase and thermolysin families of enzymes. The active site zinc ligands are all histidines (His-218, His-222, and His-228). The presence of a second zinc ion in a structural role is a unique feature of the matrix metalloproteinases. The binding properties of the active site cleft are more dependent on the main chain conformation of the enzyme (and substrate) compared with thermolysin. A mechanism of action for peptide cleavage similar to that of thermolysin is proposed for fibroblast collagenase.
Spurlino
J C
JC
Sterling Winthrop Pharmaceuticals Research Division, Collegeville, Pennsylvania 19426.
Smallwood
A M
AM
Carlton
D D
DD
Banks
T M
TM
Vavra
K J
KJ
Johnson
J S
JS
Cook
E R
ER
Falvo
J
J
Wahl
R C
RC
Pulvino
T A
TA
D000595:Amino Acid Sequence; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism; D017364:Collagenases / Q000737:chemistry* / Q000378:metabolism; D003196:Computer Graphics; D018360:Crystallography, X-Ray; D005347:Fibroblasts / Q000201:enzymology; D006801:Humans; D061965:Matrix Metalloproteinase Inhibitors; D008969:Molecular Sequence Data; D011487:Protein Conformation; D015032:Zinc / Q000737:chemistry
D061965:Matrix Metalloproteinase Inhibitors; D017364:Collagenases; D015032:Zinc; D002118:Calcium